<P> Although the Progressive Era was characterized by public support for World War I under Woodrow Wilson, there was also a substantial opposition to World War I . </P> <P> In the 1940s typically historians saw the Progressive Era as a prelude to the New Deal and dated it from 1901 (when Roosevelt became president) to the start of World War I in 1914 or 1917 . Historians have moved back in time emphasizing the Progressive reformers at the municipal and state levels in the 1890s . </P> <P> Much less settled is the question of when the era ended . Some historians who emphasize civil liberties decry their suppression during World War I and do not consider the war as rooted in Progressive policy . A strong anti-war movement headed by noted Progressives including Jane Addams, was suppressed after Wilson's 1916 re-election, a victory largely enabled by his campaign slogan, "He kept us out of the war ." The slogan was no longer accurate by April 6 of the following year, when Wilson surprised much of the Progressive base that twice elected him and asked a joint session of Congress to declare war on Germany . The Senate voted 82--6 in favor; the House agreed, 373--50 . Some historians see the so - called "war to end all wars" as a globalized expression of the American Progressive movement, with Wilson's support for a League of Nations as its climax . </P> <P> The politics of the 1920s was unfriendly toward the labor unions and liberal crusaders against business, so many if not most historians who emphasize those themes write off the decade . Urban cosmopolitan scholars recoiled at the moralism of prohibition, the intolerance of the nativists and the KKK, and on those grounds denounced the era . Richard Hofstadter, for example, in 1955 wrote that prohibition, "was a pseudo-reform, a pinched, parochial substitute for reform" that "was carried about America by the rural - evangelical virus". However, as Arthur S. Link emphasized, the Progressives did not simply roll over and play dead . Link's argument for continuity through the twenties stimulated a historiography that found Progressivism to be a potent force . Palmer, pointing to leaders like George Norris, says, "It is worth noting that progressivism, whilst temporarily losing the political initiative, remained popular in many western states and made its presence felt in Washington during both the Harding and Coolidge presidencies ." Gerster and Cords argue that, "Since progressivism was a' spirit' or an' enthusiasm' rather than an easily definable force with common goals, it seems more accurate to argue that it produced a climate for reform which lasted well into the 1920s, if not beyond ." Some social historians have posited that the KKK may in fact fit into the Progressive agenda, if Klansmen are protrayed as "ordinary white Protestants" primarily interested in purification of the system, which had long been a core Progressive goal . This however ignores the violence and racism central to Klan ideology and activities, that had nothing to do with improving society, so much as enforcing racial hierarchies . </P>

Which was the most important progressive reform of the era