The People's Party (established 1891), better known as the Populist Party, had its roots in the same farmer-labor partnership that created the Greenback Party (established 1874). Opposed to the elites of the banking and railroad industries, the Populist movement promised agrarian and labor reform. Its first presidential candidate, James B. Weaver, captured 22 electoral votes from 6 western states with 8.5% of the vote in 1892 as Democrat Grover Cleveland won his rematch against Republican Benjamin Harrison. Also in the West, multiple Populist governors, Senators, and Representatives held power throughout the decade. The Populists nominated the same presidential candidate as the Democrats in 1896, William Jennings Bryan, because of his stance on a silver bi-metal currency, though the Populist vice-presidential candidate, party leader Thomas E. Watson, differed from the Democratic candidate. Bryan's failure to defeat Republican William McKinley spelled the decline of the People's Party. The Socialist Party (established 1901) is usually associated with Eugene V. Debs, the face of the American socialist movement at its peak. He ran for president five times from 1900 to 1920, and managed to increase his vote counts with each successive campaign. He attracted over 900,000 votes twice: in 1912 with 6% of the vote, almost making it a four-way race, and in 1920, when Debs famously ran his campaign while imprisoned. Starting in 1928, his successor, Norman Thomas, ran for president six consecutive times, though the party was not quite able to replicate Debs's success. There were three notable iterations of the Progressive Party in the 20th century, each with its own ideology and goals.
Former President Theodore Roosevelt's Progressive Party (established 1912), better known as the Bull Moose Party, was created after he was unable to reclaim the Republican nomination from his former ally William Howard Taft. Roosevelt pitted his platform of New Nationalism, which promised reforms inspired by the Progressive movement, against Democrat Woodrow Wilson's more conservative New Freedom. In the most successful American third party campaign ever, Roosevelt's 27% was still only enough to win 6 states; the split of the Republican voter base between him and Taft ensured a dominant victory for Democrat Woodrow Wilson despite only receiving 42% of the vote.
Senator Robert M. La Follette, Sr.'s Progressive Party (established 1924) was created for him to run for president on his own brand of Progressive ideals different from those of Roosevelt, his onetime rival. Running on promises resembling those of the earlier Populists, La Follette grabbed 17% of the vote in the 1924 election with 13 electoral votes from his home state of Wisconsin. He came close to Democrat nominee John W. Davis in votes, but neither could prevent Republican Calvin Coolidge's re-election.
Former Vice President Henry Wallace's Progressive Party (established 1948) formed out of Wallace's disagreements with his replacement as FDR's vice president, incumbent Harry S. Truman, who had fired Wallace from his position as Secretary of Commerce. In addition to promoting leftist reforms, Wallace also wanted cooperation with the Soviet Union, though his association with the Soviets and Communism hurt his popularity. In spite of this, he still won 2.4% of the vote with well over a million votes in a contentious election that Truman barely won over Thomas Dewey.
The American Independent Party (established 1967), or AIP, was a sort of spiritual successor to the Dixiecrats from two decades before. In an effort to combat the desegregation being pushed by a pro-civil rights federal government, George Wallace, the segregationist governor of Alabama, ran for president on the ticket of the AIP, led by Bill and Eileen Shearer. Running on a platform of segregation once again proved appealing to the South, as Wallace won 46 electoral votes from 5 states, and 13% of the vote with nearly 10 million votes. Many Wallace supporters, including the organizers of the AIP, later joined the U.S. Taxpayers Party, which was renamed the Constitution Party, and still exists as a small party to the right of the Republicans.