The outbreak of the American Civil War in 1861 led to the expansion of the federal government and notable growth in the district's population, including a large influx of freed slaves. President Abraham Lincoln signed the Compensated Emancipation Act in 1862, which ended slavery in the district of Columbia and freed about 3,100 enslaved persons, nine months prior to the Emancipation Proclamation. In 1868, Congress granted the district's African American male residents the right to vote in municipal elections.