Croker was soon involved in taking bribes from the owners of brothels, saloons and illegal gambling dens. Charles Parkhurst, the president of the Society for the Prevention of Crime, led the campaign against city corruption. In February, 1892, Parkhurst made a tremendous impact on the people of the city with a powerful sermon attacking Tammany Hall corruption but Croker remained in power until 1901 when he was defeated by Seith Low.
Croker's political dealings had made him a wealthy man, and in 1903 he purchased a large estate in Ireland where he bred racehorses. In 1907 he won the Derby with his horse, Orby. Richard Croker died in 1922.