In 1916, a portfolio of nine major parks was published to generate interest. Printed on each brochure was a map showing the parks and principal railroad connections.
In 1934, a series of ten postage stamps were issued to commemorate the reorganization and expansion of the National Park Service.
National parks and national monuments in the United States were originally individually managed under the auspices of the Department of the Interior. The movement for an independent agency to oversee these federal lands was spearheaded by
business magnate and
Stephen Mather, as well as
J. Horace McFarland. With the help of journalist
Robert Sterling Yard, Mather ran a publicity campaign for the
Department of the Interior. They wrote numerous articles that praised the scenic and historic qualities of the parks and their possibilities for educational, inspirational, and recreational benefits.
 This campaign resulted in the creation of a National Park Service. On August 25, 1916, President
Woodrow Wilson signed a bill that mandated the agency "to conserve the scenery and the natural and historic objects and wildlife therein, and to provide for the enjoyment of the same in such manner and by such means as will leave them unimpaired for the enjoyment of future generations."
 Mather became the first director of the newly formed NPS.
On March 3, 1933, President
Herbert Hoover signed the Reorganization Act of 1933. The act would allow the President to reorganize the executive branch of the United States government. It wasn't until later that summer when the new President,
Franklin D. Roosevelt, made use of this power. Deputy Director
Horace M. Albright had suggested to President Roosevelt that the historic sites from the American Civil War should be managed by the National Park Service, rather than the War Department. President Roosevelt agreed and issued two
Executive orders to make it happen. These two executive orders not only transferred to the National Park Service all the War Department historic sites, but also the national monuments managed by the Department of Agriculture and the parks in and around the capital, which had been run by an independent office.
Conrad Wirth became director of the National Park Service and went to work on bringing park facilities up to the standards that the public expected. The demand for parks after the end of the
World War II had left the parks overburdened with demands that could not be met. In 1952, with the support of President
Dwight D. Eisenhower, he began
Mission 66, a ten-year effort to upgrade and expand park facilities for the 50th anniversary of the Park Service. New parks were added to preserve unique resources and existing park facilities were upgraded and expanded.
In 1966, as the Park Service turned 50 years old, emphasis began to turn from just saving great and wonderful scenery and unique natural features to making parks accessible to the public. Director
George Hartzog began the process with the creation of the
National Lakeshores and then
National Recreation Areas.
A National Park Service
Since its inception in 1916, the National Park Service has managed each of the United States' national parks, which have grown in number over the years to 59.
Yellowstone National Park was the first
national park in the United States. In 1872, there was no
state government to manage it, so the
federal government assumed direct control.
Yosemite National Park began as a
state park; the land for the park was donated by the federal government to the state of
California in 1864 for perpetual conservation. Yosemite was later returned to federal ownership.
At first, each national park was managed independently, with varying degrees of success. In Yellowstone, the civilian staff was replaced by the
U.S. Army in 1886. Due to the irregularities in managing these national treasures, Stephen Mather petitioned the federal government to improve the situation. In response, Secretary of the Interior
Franklin K. Lane challenged him to
lobby for creating a new agency, the National Park Service, to manage all national parks and some national monuments. Mather was successful with the ratification of the
National Park Service Organic Act in 1916.
 Later, the agency was given authority over other protected areas, many with varying designations as Congress created them.