The Country Party was formally founded in 1913 in Western Australia, and nationally in 1920 from a number of state-based parties such as the Victorian Farmers' Union (VFU) and the
Farmers and Settlers Party of New South Wales. Australia's first Country Party was founded in 1912 by Harry J. Stephens, editor of The Farmer & Settler, but under fierce opposition from rival newspapers, failed to gain momentum.
The VFU won a seat in the House of Representatives at the Corangamite by-election held in December 1918, with the help of the newly introduced preferential voting system. At the 1919 federal election the state-based Country Parties won federal seats in New South Wales, Victoria and Western Australia. They also began to win seats in state parliaments. In 1920 the Country Party was established as a national party led by William McWilliams from Tasmania. In his first speech as leader, McWilliams laid out the principles of the new party, stating "we crave no alliance, we spurn no support but we intend drastic action to secure closer attention to the needs of primary producers" McWilliams was deposed as party leader in favour of Dr Earle Page in April 1921 following instances where McWilliams voted against the party line. McWilliams would later leave the Country Party to sit as an Independent.
According to historian B. D. Graham (1959), the graziers who operated the sheep stations were politically conservative. They disliked the Labor Party, which represented their workers, and feared that Labor governments would pass unfavorable legislation and listen to foreigners and communists. The graziers were satisfied with the marketing organisation of their industry, opposed any change in land tenure and labour relations, and advocated lower tariffs, low freight rates, and low taxes. On the other hand, Graham reports, the small farmers, not the graziers, founded the Country party. The farmers advocated government intervention in the market through price support schemes and marketing pools. The graziers often politically and financially supported the Country party, which in turn made the Country party more conservative.
The Country Party's first election as a united party, in 1922, saw it in an unexpected position of power. It won enough seats to deny the Nationalists an overall majority, and was the Nationalists' only realistic coalition partner. However, Page let it be known that his party would not serve under Hughes, and forced his resignation. Page then entered negotiations with the Nationalists' new leader, Stanley Bruce, for a coalition government. Page's terms were stiff—five seats in a Cabinet of 11, including the Treasurer portfolio and the second rank in the ministry for himself. Nonetheless, Bruce readily agreed, and the "Bruce-Page Ministry" was formed—thus beginning the tradition of the party's leader ranking second in Coalition cabinets.
Page remained dominant in the party until 1939 and briefly served as an interim Prime Minister between the death of Joseph Lyons and the election of Robert Menzies as his successor, but Page's refusal to serve under Menzies led to his resignation as leader. The coalition was re-formed under Archie Cameron in 1940, and continued until October 1941 despite the election of Arthur Fadden as leader after the 1940 Election. Fadden was well regarded within conservative circles and proved to be a loyal deputy to Menzies in the difficult circumstances of 1941. When Menzies was forced to resign as Prime Minister, the UAP was so bereft of leadership that Fadden briefly succeeded him (despite the Country Party being the junior partner in the governing coalition). However, the two independents who had been propping up the government rejected Fadden's budget and brought the government down. Fadden stood down in favour of Labor leader John Curtin.
The Fadden-led Coalition made almost no headway against Curtin, and was severely defeated in the 1943 election. After that loss, Fadden became deputy Leader of the Opposition under Menzies, a role that continued after Menzies folded the UAP into the Liberal Party of Australia in 1944. Fadden remained a loyal partner of Menzies, though he was still keen to assert the independence of his party. Indeed, in the lead up to the 1949 federal election, Fadden played a key role in the defeat of the Chifley Labor government, frequently making inflammatory claims about the "socialist" nature of the Labor Party, which Menzies could then "clarify" or repudiate as he saw fit, thus appearing more "moderate". In 1949, Fadden became Treasurer in the second Menzies government and remained so until his retirement in 1958. His successful partnership with Menzies was one of the elements that sustained the coalition, which remained in office until 1972 (Menzies himself retired in 1966).
John McEwen House, The National Party's headquarters in Canberra
Fadden's successor, Trade Minister John McEwen, took the then unusual step of declining to serve as Treasurer, believing he could better ensure that the interests of Australian primary producers were safeguarded. Accordingly, McEwen personally supervised the signing of the first post-war trade treaty with Japan, new trade agreements with New Zealand and Britain, and Australia's first trade agreement with the USSR (1965). In addition to this he insisted on developing an all encompassing system of tariff protection that would encourage the development of those secondary industries that would "value add" Australia's primary produce. His success in this endeavour is sometimes dubbed "McEwenism". This was the period of the Country Party's greatest power, as was demonstrated in 1962 when McEwen was able to insist that Menzies sack a Liberal Minister who claimed that Britain's entry into the was unlikely to severely impact on the Australian economy as a whole.
Menzies retired in 1966 and was succeeded by Harold Holt. McEwen thus became the longest-tenured member of the government, with the informal right to veto government policy. The most significant instance that McEwen exercised this came when Holt disappeared in December 1967. John Gorton became the new Liberal Prime Minister in January 1968. McEwen was sworn in as an interim Prime Minister pending the election of the new Liberal leader. Logically, the Liberals' deputy leader, William McMahon, should have succeeded Holt. However, McMahon was a staunch free-trader, and there were also rumors that he was homosexual. As a result, McEwen told the Liberals that he and his party would not serve under McMahon. McMahon stood down in favour of John Gorton. It would be only after McEwen announced his retirement that MacMahon would be able to successfully challenge Gorton for the Liberal leadership. McEwen's reputation for political toughness led to him being nicknamed "Black Jack" by his allies and enemies alike.
At the state level, from 1957 to 1989, the Country Party under Frank Nicklin and Joh Bjelke-Petersen dominated governments in Queensland—the last six of those years ruling in its own right, without the Liberals. It also took part in governments in New South Wales, Victoria, and Western Australia.
However, successive electoral redistributions after 1964 indicated that the Country Party was losing ground electorally to the Liberals as the rural population declined, and the nature of some parliamentary seats on the urban/rural fringe changed. A proposed merger with the Democratic Labor Party (DLP) under the banner of "National Alliance" was rejected when it failed to find favour with voters at the 1974 state election.
Also in 1974, the Northern Territory members of the party joined with its Liberal party members to form the independent Country Liberal Party. This party continues to represent both parent parties in that territory. A separate party, the Joh-inspired NT Nationals, competed in the 1987 election with former Chief Minister Ian Tuxworth winning his seat of Barkly by a small margin. However, this splinter group were not endorsed by the national executive and soon disappeared from the political scene.
"Countrymindedness" was a slogan that summed up the ideology of the Country Party from 1920 through the early 1970s. It was an ideology that was physiocratic, populist, and decentralist; it fostered rural solidarity and justified demands for government subsidies. "Countrymindedness" grew out of the failure of the country areas to participate in the rapid economic and population expansions that occurred after 1890. The growth of the ideology into urban areas came as most country people migrated to jobs in the cities. Its decline was due mainly to the reduction of real and psychological differences between country and city brought about by the postwar expansion of the Australian urban population and to the increased affluence and technological changes that accompanied it.
National Country Party, and National Party
In 1975 the Country Party changed its name to the National Country Party as part of a strategy to expand into urban areas. This had some success in Queensland under Joh Bjelke-Petersen, but nowhere else. In Western Australia, the party briefly walked out of the coalition agreement in Western Australia in May 1975, returning within the month. However, the party split in two over the decision and other factors in late 1978, with a new National Party forming and becoming independent, holding three seats in the Western Australian lower house, while the National Country Party remained in coalition and also held three seats. They reconciled after the Burke Labor government came to power in 1983.
The 1980s were dominated by the feud between Bjelke-Petersen and the federal party leadership. Bjelke-Petersen briefly triumphed in 1987, forcing the Nationals to tear up the Coalition agreement and support his bid to become Prime Minister. The "Joh for Canberra" campaign backfired spectacularly when a large number of three-cornered contests allowed Labor to win a third term under Bob Hawke. It also proved to be the Queensland Nationals' last hurrah; Bjelke-Petersen was forced into retirement a few months after the federal election, and his party was heavily defeated in 1989. The Nationals experienced difficulties in the late 1990s from two fronts – firstly from the Liberal Party, who were winning seats on the basis that the Nationals were not seen to be a sufficiently separate party, and from the One Nation Party riding a swell of rural discontent with many of the policies such as multiculturalism and gun control embraced by all of the major parties. The rise of Labor in formerly safe National-held areas in rural Queensland, particularly on the coast, has been the biggest threat to the Queensland Nationals.
In 2018, it was revealed that the NSW National party and its youth wing, the Young Nationals had been infiltrated by neo-Nazis with more than 30 members being investigated for alleged links to neo-Nazism. Several suspected neo-Nazis were expelled from the party and its youth wing. 
Party leader Michael McCormack denounced these attempts stating that "The Nationals will not tolerate extremism or the politics of hate. People found to engage with such radicalism are not welcome in our party. We are a grassroots party proudly championing what matters most to our regional and rural communities – always has been, always will be." However former leader Barnaby Joyce initially called the reports "McCarthyist witch-hunts for the reds under the bed" and questioning the evidence behind the claims. He later went back on these claims and called for the group to be dismissed from the party.