Progressivism was a political and socioeconomic movement central to American national politics from the Gilded Age (1890s) to the end of the Roaring Twenties. At its heart, it was a populist, bipartisan reaction to the excesses of the wealthy ‘robber-baron’ classes and the threat of revolution from the disenfranchised working class – many of whom did not share in the dramatic economic growth of the age – accompanied by a distinctly anti-immigrant nativism.