In the same way a tamed Labor Day celebration of unions stole the thunder of socialist May Day, a political movement arose in the United States to attempt to prevent revolutionary change by offering mild reforms.
Marx and early socialists were concerned with Europe, not the United States and their ideas were mostly imported through immigration from Central Europe and Italy, at a time when industrialization was demanding an ever greater number of workers for new and expanding factories. Up to the 1890s, when the American Frontier was effectively declared closed, the existence of what to some were vast "vacant" lands (not how Indians or Mexicans viewed them), had been a kind of social and economic safety valve. If you didn’t like being on the bottom of the pecking order, you just went West.
Once the Frontiers closed or became crowded, however, the urgent problems of capitalism began to take on urgency. Because capitalism encouraged speculative investment, the entire economic system was chained to a recurring cycle of booms and busts that left millions of workers out of work. This happened again and again and again, every 5 to 15 years. The Great Depression of the 1930s was the deepest and longest bust, but it was by far not the only one. The cycle has continued happening through the Great Recession of 2007-2009.
One answer, from well-meaning but essentially capitalist quarters, were the reformist "Progressives." In the presidential election of 1912 all three major candidates — Teddy Roosevelt for the "Bull Moose" Progressive Party (a split from the Republicans), Republican William Howard Taft and Democrat Woodrow Wilson — claimed to be "progressive" at one point or another.
U.S. Progressivism of the 1880s to the 1920s was a decidedly centrist, reformist effort to ameliorate the ill effects of capitalism, regulating it rather than getting rid of it; its principal and last policy achievements in the USA were the Federal Reserve, the Food and Drug Administration (which ended the actual "snake oil" salesmen) and the federal income tax. Less effective was anti-trust legislation, which did not stop corporations' unfettered growth in power.
