Creation and BAA–NBL merger (1946–1956)
The Basketball Association of America was founded in 1946 by owners of the major ice hockey arenas in the Northeastern and Midwestern United States and Canada. On November 1, 1946, in Toronto, Ontario, Canada, the Toronto Huskies hosted the New York Knickerbockers at Maple Leaf Gardens, in a game the NBA now refers to as the first played game in NBA history. The first basket was made by Ossie Schectman of the Knickerbockers. Although there had been earlier attempts at professional basketball leagues, including the American Basketball League and the NBL, the BAA was the first league to attempt to play primarily in large arenas in major cities. During its early years, the quality of play in the BAA was not significantly better than in competing leagues or among leading independent clubs such as the Harlem Globetrotters. For instance, the 1948 ABL finalist Baltimore Bullets moved to the BAA and won that league's 1948 title, and the 1948 NBL champion Minneapolis Lakers won the 1949 BAA title. Prior to the 1948–49 season, however, NBL teams from Fort Wayne, Indianapolis, Minneapolis, and Rochester jumped to the BAA, which established the BAA as the league of choice for collegians looking to turn professional.
On August 3, 1949, the remaining NBL teams–Syracuse, Anderson, Tri-Cities, Sheboygan, Denver, and Waterloo–merged into the BAA. In deference to the merger and to avoid possible legal complications, the league name was changed to the present National Basketball Association, even though the merged league retained the BAA's governing body, including Podoloff. To this day, the NBA claims the BAA's history as its own. It now reckons the arrival of the NBL teams as an expansion, not a merger, and does not recognize NBL records and statistics.
The new league had seventeen franchises located in a mix of large and small cities, as well as large arenas and smaller gymnasiums and armories. In 1950, the NBA consolidated to eleven franchises, a process that continued until 1953–54, when the league reached its smallest size of eight franchises: the New York Knicks, Boston Celtics, Philadelphia Warriors, Minneapolis Lakers, Rochester Royals, Fort Wayne Pistons, Tri-Cities Blackhawks, and Syracuse Nationals, all of which remain in the league today. The process of contraction saw the league's smaller-city franchises move to larger cities. The Hawks shifted from the Tri-Cities to Milwaukee in 1951, and then to St. Louis in 1955. The Rochester Royals moved from Rochester, New York, to Cincinnati in 1957 and the Pistons relocated from Fort Wayne, Indiana, to Detroit in 1957.
Japanese-American Wataru Misaka broke the NBA color barrier in the 1947–48 season when he played for the New York Knicks. He remained the only non-white player in league history prior to the first African-American, Harold Hunter, signing with the Washington Capitols in 1950. Hunter was cut from the team during training camp, but several African-American players did play in the league later that year, including Chuck Cooper with the Celtics, Nathaniel "Sweetwater" Clifton with the Knicks, and Earl Lloyd with the Washington Capitols. During this period, the Minneapolis Lakers, led by center George Mikan, won five NBA Championships and established themselves as the league's first dynasty. To encourage shooting and discourage stalling, the league introduced the 24-second shot clock in 1954. If a team does not attempt to score a field goal (or the ball fails to make contact with the rim) within 24 seconds of obtaining the ball, play is stopped and the ball given to its opponent.
Celtics' dominance, league expansion and competition (1956–1979)
In 1957, rookie center Bill Russell joined the Boston Celtics, which already featured guard Bob Cousy and coach Red Auerbach, and went on to lead the club to eleven NBA titles in thirteen seasons. Center Wilt Chamberlain entered the league with the Warriors in 1959 and became a dominant individual star of the 1960s, setting new single game records in scoring (100) and rebounding (55). Russell's rivalry with Chamberlain became one of the greatest rivalries in the history of American team sports.
The 1960s were dominated by the Celtics. Led by Russell, Bob Cousy and coach Red Auerbach, Boston won eight straight championships in the NBA from 1959 to 1966. This championship streak is the longest in NBA history. They did not win the title in 1966–67, but regained it in the 1967–68 season and repeated in 1969. The domination totaled nine of the ten championship banners of the 1960s.
Through this period, the NBA continued to evolve with the shift of the Minneapolis Lakers to Los Angeles, the Philadelphia Warriors to San Francisco, the Syracuse Nationals to Philadelphia to become the Philadelphia 76ers, and the St. Louis Hawks moving to Atlanta, as well as the addition of its first expansion franchises. The Chicago Packers (now Washington Wizards) became the ninth NBA team in 1961. From 1966 to 1968, the league expanded from 9 to 14 teams, introducing the Chicago Bulls, Seattle SuperSonics (now Oklahoma City Thunder), San Diego Rockets (who relocated to Houston four years later), Milwaukee Bucks, and Phoenix Suns.
In 1967, the league faced a new external threat with the formation of the American Basketball Association (ABA). The leagues engaged in a bidding war. The NBA landed the most important college star of the era, Kareem Abdul-Jabbar (then known as Lew Alcindor). However, the NBA's leading scorer, Rick Barry, jumped to the ABA, as did four veteran referees—Norm Drucker, Earl Strom, John Vanak, and Joe Gushue.
In 1969, Alan Siegel, who oversaw the design of Jerry Dior's Major League Baseball logo a year prior, created the modern NBA logo inspired by the MLB's. It incorporates the silhouette of the legendary Jerry West based on a photo by Wen Roberts, although NBA officials denied a particular player as being its influence because, according to Siegel, "They want to institutionalize it rather than individualize it. It's become such a ubiquitous, classic symbol and focal point of their identity and their licensing program that they don't necessarily want to identify it with one player." The iconic logo debuted in 1971 (with a small change to the typeface on the NBA wordmark in 2017) and would remain a fixture of the NBA brand.
The ABA succeeded in signing a number of major stars in the 1970s, including Julius Erving of the Virginia Squires, in part because it allowed teams to sign college undergraduates. The NBA expanded rapidly during this period, one purpose being to tie up the most viable cities. From 1966 to 1974, the NBA grew from nine franchises to 18. In 1970, the Portland Trail Blazers, Cleveland Cavaliers, and Buffalo Braves (now the Los Angeles Clippers) all made their debuts expanding the league to 17. The New Orleans Jazz (now in Utah) came aboard in 1974 bringing the total to 18. Following the 1976 season, the leagues reached a settlement that provided for the addition of four ABA franchises to the NBA, raising the number of franchises in the league at that time to 22. The franchises added were the San Antonio Spurs, Denver Nuggets, Indiana Pacers, and New York Nets (now the Brooklyn Nets). Some of the biggest stars of this era were Kareem Abdul-Jabbar, Rick Barry, Dave Cowens, Julius Erving, Elvin Hayes, Walt Frazier, Moses Malone, Artis Gilmore, George Gervin, Dan Issel, and Pete Maravich. The end of the decade, however, saw declining TV ratings, low attendance and drug-related player issues – both perceived and real – that threatened to derail the league.
Surging popularity (1979–1998)
The league added the ABA's innovative three-point field goal beginning in 1979 to open up the game. That same year, rookies Larry Bird and Magic Johnson joined the Boston Celtics and Los Angeles Lakers respectively, initiating a period of significant growth in fan interest in the NBA throughout the country and the world. The two had faced each other in the 1979 NCAA Division I Basketball Championship Game, and they later played against each other in three NBA Finals (1984, 1985, and 1987, featuring 11 players and coaches who would later be inducted to the Basketball Hall of Fame). Like the 1960s, when the Celtics and Lakers faced each other in six NBA Finals, the two teams again dominated the NBA. In the 10 seasons of the 1980s, Johnson led the Lakers to five titles in eight Finals while Bird led the Celtics to three titles in five Finals. Also in the early 1980s, the NBA added one more expansion franchise, the Dallas Mavericks, bringing the total to 23 teams. Later on, Larry Bird won the first three three-point shooting contests. Former league commissioner David Stern, who took office on February 1, 1984, oversaw the expansion and growth of the NBA to a global commodity.
Michael Jordan entered the league in 1984 with the Chicago Bulls, providing an even more popular star to support growing interest in the league. This resulted in more cities demanding teams of their own. In 1988 and 1989, four cities got their wishes as the Charlotte Hornets, Miami Heat, Orlando Magic, and Minnesota Timberwolves made their NBA debuts, bringing the total to 27 teams. The Detroit Pistons won the back-to-back in 1989 and 1990, led by coach Chuck Daly and guard Isiah Thomas. Jordan and Scottie Pippen led the Bulls to two three-peats in eight years during the 1991–98 seasons. Hakeem Olajuwon won back-to-back titles with the Houston Rockets in 1994 and 1995.
The 1992 Olympic basketball Dream Team, the first to use current NBA stars, featured Michael Jordan as the anchor, along with Bird, Johnson, David Robinson, Patrick Ewing, Scottie Pippen, Clyde Drexler, Karl Malone, John Stockton, Chris Mullin, Charles Barkley, and star NCAA amateur Christian Laettner. The team was elected to the Naismith Memorial Basketball Hall of Fame, while 11 of the 12 players on the roster (all but Laettner) and three of the four coaches have been elected to the Hall of Fame as individuals.
In 1995, the NBA expanded to Canada with the addition of the Vancouver Grizzlies and the Toronto Raptors. In 2001, the Vancouver Grizzlies relocated to Memphis, which left the Raptors as the only Canadian team in the NBA.
In 1996, the NBA created a women's league, the Women's National Basketball Association (WNBA).
In 1998, the NBA owners began a lockout which lasted 191 days and was settled on January 18, 1999. As a result of this lockout the 1998–99 NBA season was reduced from 82 to 50 games (61% of a normal season), and the All-Star Game was cancelled. The San Antonio Spurs won their first championship, and first by a former ABA team, by beating the New York Knicks, who were the first, and are the only, eighth seed to ever make it to the NBA Finals.
Modern era (1998–present)
Since the breakup of the Chicago Bulls championship roster in the summer of 1998, the Western Conference has dominated. The Los Angeles Lakers of coach Phil Jackson and the San Antonio Spurs of Gregg Popovich combined to make 13 Finals in 16 seasons, with 10 titles. Tim Duncan and David Robinson won the 1999 championship with the Spurs, and Shaquille O'Neal and Kobe Bryant started the 2000s with three consecutive championships for the Lakers. The Spurs reclaimed the title in 2003 against the Nets. In 2004, the Lakers returned to the Finals, only to lose in five games to the Detroit Pistons.
After the Spurs took home the Larry O'Brien Championship Trophy in 2005, the 2006 Finals featured two franchises making their inaugural Finals appearances. The Miami Heat, led by their star shooting guard, Dwyane Wade, and Shaquille O'Neal, who had been traded from the Lakers during summer 2004, won the series over the Dallas Mavericks in six after losing the first two games. The Lakers/Spurs dominance continued in 2007 with a four-game sweep by the Spurs over the Cleveland Cavaliers, who were led by LeBron James. The 2008 Finals saw a rematch of the league's highest profile rivalry, the Boston Celtics and Los Angeles Lakers, with the Celtics winning, for their 17th championship, thanks to their new big three of Paul Pierce, Ray Allen, and Kevin Garnett.
In 2009, Kobe Bryant and the Lakers returned to the Finals, this time defeating the Dwight Howard-led Orlando Magic. Bryant won his first Bill Russell NBA Finals Most Valuable Player Award in his 13th season after leading the Lakers to their first NBA championship since the departure of Shaquille O'Neal.
The 2010 NBA All-Star Game was held at Cowboys Stadium in front of the largest crowd ever, 108,713. At the end of that season, the Celtics and the Lakers renewed their rivalry from 2008 when they met again in the NBA Finals for a record 12th time. The Lakers won the title by winning Game 7, 83–79. Before the start of the 2010–11 season the NBA had an exciting summer with one of the most anticipated free agent classes of all time. Two of which signed, and one resigned, with the Miami Heat, leading to a season that was heavily centered on their eventual success or failure at taking home the championship. The Heat, led by LeBron James, Dwyane Wade, and Chris Bosh, did in fact make the Finals against the Dallas Mavericks, in a rematch for the franchises of the 2006 Finals. The Mavericks, led by Dirk Nowitzki (the eventual NBA Finals MVP), took the series in six games. This was the Mavericks' first title. Veterans Shawn Marion, Jason Kidd, Jason Terry, and Peja Stojaković celebrated their first NBA championship.
On July 1, 2011, at 12:01 am, the NBA announced another lockout. After the first few weeks of the season were canceled, the players and owners ratified a new collective bargaining agreement on December 8, 2011, setting up a shortened 66-game season. Following the shortened season, the Miami Heat made a return to the Finals with the trio of Dwyane Wade, LeBron James, and Chris Bosh against Oklahoma City Thunder's Kevin Durant, Russell Westbrook, and James Harden. The Heat went on to defeat the Thunder in five games, capturing their second NBA title in six years. Their success would continue into the following season, which concluded with their victory over the San Antonio Spurs in the 2013 NBA Finals. The two teams would meet for a rematch in the following year's Finals, where the Spurs defeated the Heat in five games. Off the court, commissioner David Stern retired on February 1, 2014, exactly 30 years to the day from taking office. He was succeeded by his deputy, Adam Silver.
Following the 2014 Finals, LeBron James announced that he would return to the Cleveland Cavaliers. James led the Cavaliers to their second Finals appearance, where they lost to the Golden State Warriors in six games. The following year, in a rematch, the 2016 NBA Finals concluded with the Cavaliers defeating the Warriors in seven games to win their first NBA Championship. The dominance of those two teams continued in 2017, when the Warriors, having signed Kevin Durant as a free agent, took the third straight Finals matchup between the two teams in five games, with Durant named Finals MVP, and again in 2018 when they went to a fourth straight Finals matchup.
During free agency in 2018, LeBron James signed with the Lakers.
Following pioneers like Vlade Divac (Serbia) and Dražen Petrović (Croatia) who joined the NBA in the late 1980s, an increasing number of international players have moved directly from playing elsewhere in the world to starring in the NBA. Since 2006, the NBA has faced EuroLeague teams in exhibition matches in the NBA Europe Live Tour, and since 2009, in the EuroLeague American Tour. The 2013–14 season opened with a record 92 international players on the opening night rosters, representing 39 countries and comprising over 20% of the league. The beginning of the 2017-18 season saw a record 108 international players representing 42 different countries marking 4 consecutive years of at least 100 international players and each team having at least one international player. In 2018, the Phoenix Suns hired Serbian coach Igor Kokoškov as their new head coach, replacing Canadian interim coach Jay Triano, making Kokoškov the first European coach to become a head coach for a team in the NBA.
In 2001, an affiliated minor league, the National Basketball Development League, now called the NBA G League, was created. Before the league was started, there were strong rumors that the NBA would purchase the Continental Basketball Association, and call it its developmental league.
Two years after the Hornets' relocation to New Orleans, the NBA returned to North Carolina, as the Charlotte Bobcats were formed as an expansion team in 2004.
The Hornets temporarily relocated to Oklahoma City in 2005 for two seasons because of damage caused by Hurricane Katrina. The team returned to New Orleans in 2007.
A new official game ball was introduced on June 28, 2006, for the 2006–07 season, marking the first change to the ball in over 35 years and only the second ball in 60 seasons. Manufactured by Spalding, the new ball featured a new design and new synthetic material that Spalding claimed offered a better grip, feel, and consistency than the original ball. However, many players were vocal in their disdain for the new ball, saying that it was too sticky when dry, and too slippery when wet.
Commissioner Stern announced on December 11, 2006, that beginning January 1, 2007, the NBA would return to the traditional leather basketball in use prior to the 2006–07 season. The change was influenced by frequent player complaints and confirmed hand injuries (cuts) caused by the microfiber ball. The Players' Association had filed a suit on behalf of the players against the NBA over the new ball. As of the 2017–18 season, the NBA team jerseys are manufactured by Nike, replacing the previous supplier, Adidas. All teams will wear jerseys with the Nike logo except the Charlotte Hornets, whose jerseys will instead have the Jumpman logo associated with longtime Nike endorser Michael Jordan, who owns the Hornets.
The Federal Bureau of Investigation (FBI) began an investigation on July 19, 2007, over allegations that veteran NBA referee Tim Donaghy bet on basketball games he officiated over the past two seasons and that he made calls affecting the point spread in those games. On August 15, 2007, Donaghy pleaded guilty to two federal charges related to the investigation. Donaghy claimed in 2008 that certain referees were friendly with players and "company men" for the NBA, and he alleged that referees influenced the outcome of certain playoff and finals games in 2002 and 2005. NBA commissioner David Stern denied the allegations and said Donaghy was a convicted felon and a "singing, cooperating witness". Donaghy served 15 months in prison and was released in November 2009. According to an independent study by Ronald Beech of Game 6 of the 2002 Western Conference Finals between the Los Angeles Lakers and Sacramento Kings, although the refs increased the Lakers' chances of winning through foul calls during the game, there was no collusion to fix the game. On alleged "star treatment" during Game 6 by the refs toward certain players, Beech claimed, "there does seem to be issues with different standards and allowances for different players." 
The NBA Board of Governors approved the request of the Seattle SuperSonics to relocate to Oklahoma City on April 18, 2008. The team, however, could not move until it had settled a lawsuit filed by the city of Seattle, which was intended to keep the SuperSonics in Seattle for the remaining two seasons of the team's lease at KeyArena. Following a court case, the city of Seattle settled with the ownership group of the SuperSonics on July 2, 2008, allowing the team to move to Oklahoma City immediately in exchange for terminating the final two seasons of the team's lease at KeyArena. The Oklahoma City Thunder began playing in the 2008–09 season.
The first outdoor game in the modern era of the league was played at the Indian Wells Tennis Garden on October 11, 2008, between the Phoenix Suns and the Denver Nuggets.
A referee lockout began on September 1, 2009, when the contract between the NBA and its referees expired. The first preseason games were played on October 1, 2009, and replacement referees from the WNBA and NBA Development League were used, the first time replacement referees had been used since the beginning of the 1995–96 season. The NBA and the regular referees reached a deal on October 23, 2009.
The first official NBA league games on European ground took place in 2011. In two matchups, the New Jersey Nets faced the Toronto Raptors at the O2 Arena in London in front of over 20,000 fans.
The 2011–12 NBA season, scheduled to begin November 1, 2011, with a matchup between the defending champion Dallas Mavericks and the Chicago Bulls, was postponed due to a labor dispute. The lockout officially ended on December 8, 2011, when players and owners ratified a new collective bargaining agreement, and the season began on Christmas Day.
After the 2012–13 season, the New Orleans Hornets renamed themselves the Pelicans. During the 2013–14 season, Stern retired as commissioner after 30 years, and deputy commissioner Adam Silver ascended to the position of commissioner. During that season's playoffs, the Bobcats officially reclaimed the Hornets name, and by agreement with the league and the Pelicans, also received sole ownership of all history, records, and statistics from the Pelicans' time in Charlotte. As a result, the Hornets are now officially considered to have been founded in 1988, suspended operations in 2002, and resumed in 2004 as the Bobcats, while the Pelicans are officially treated as a 2002 expansion team. (This is somewhat similar to the relationship between the Cleveland Browns and Baltimore Ravens in the .)
Donald Sterling, who was then-owner of the Los Angeles Clippers, received a lifetime ban from the NBA on April 29, 2014, after racist remarks he made became public. Sterling was also fined US$2.5 million, the maximum allowed under the NBA Constitution.
Becky Hammon was hired by the San Antonio Spurs on August 5, 2014, as an assistant coach, becoming the second female coach in NBA history but the first full-time coach. This also makes her the first full-time female coach in any of the four major professional sports in North America.
The NBA announced on April 15, 2016, that it would allow all 30 of its member clubs to sell corporate sponsor advertisement patches on official game uniforms, beginning with the 2017–18 season. The sponsorship advertisement patches would appear on the left front of jerseys, opposite Nike's logo, marking the first time a manufacturer's logo would appear on NBA jerseys, and would measure approximately 2.5 by 2.5 inches. The NBA would become the first major North American professional sports league to allow corporate sponsorship logos on official team uniforms, and the last to have a uniform manufacturer logo appear on its team uniforms. The first team to announce a jersey sponsorship was the Philadelphia 76ers, who agreed to a deal with StubHub.
On July 6, 2017, the NBA unveiled an updated rendition of its logo; it is largely identical to the previous design, except with revised typography and a "richer" color scheme. The league began to phase in the updated logo across its properties during the 2017 NBA Summer League, but it will not immediately be used on equipment or uniforms due to lead time.
The NBA also officially released new Nike uniforms for all 30 teams beginning with the 2017–18 season. The league eliminated "home" and "away" uniform designations. Instead, each team would have four or five uniforms: the "Association" edition, which is the team's traditional white uniform, the "Icon" edition, which is the team's primary color uniform, and two other uniform editions, to be unveiled at a later date.