 Such groups have been described as "the military arm of the Democratic Party".They were instrumental in many Southern states in driving blacks away from the polls and ensuring a white Democratic takeover of legislatures and governorships in most Southern states in the 1870s, most notoriously during the controversial 1876 elections.As a result of a national Compromise of 1877 arising from the 1876 presidential election, the federal government withdrew its military forces from the South, formally ending the Reconstruction era.