The Anti-Saloon League was the leading organization lobbying for prohibition in the United States in the early 20th century.
It was a key component of the Progressive Era, and was strongest in the South and rural North, drawing heavy support from pietistic Protestant ministers and their congregations, especially Methodists, Baptists, Disciples and Congregationalists. It concentrated on legislation, and cared about how legislators voted, not whether they drank or not. Founded as a state society in Oberlin, Ohio, in 1893, its influence spread rapidly. In 1895, it became a national organization and quickly rose to become the most powerful prohibition lobby in America, pushing aside its older competitors the Woman's Christian Temperance Union and the Prohibition Party. Its triumph was nationwide prohibition locked into the Constitution with passage of the 18th Amendment in 1920. It was decisively defeated when Prohibition was repealed in 1933.
It continued however, and is today known as the American Council on Alcohol Problems.
The League was the first modern pressure group organized around one issue. Unlike earlier popular movements, it utilized bureaucratic methods learned from business to build a strong organization. The League's founder and first leader, Howard Hyde Russell (1855–1946), believed that the best leadership was selected, not elected. Russell built from the bottom up, shaping local leagues and raising the most promising young men to leadership at the local and state levels. This organizational strategy reinvigorated the temperance movement.