The political power of the white Democrats in the South came from their having disfranchised most blacks from 1890 to 1910. The South was essentially a one-party, Democratic region in which only whites voted and held office, well into the 1960s, but Congressional representation was based on the total population. The situation of disfranchisement did not change markedly until passage in the 1960s of federal civil rights legislation that protected and enforced the constitutional rights of voting and citizenship for African Americans and other minorities.