 The 1860 Census put the population at just over 75,000 persons, but by 1870 the District population had grown to nearly 132,000.Warehouses, supply depots, ammunition dumps, and factories were established to provide and distribute material for the Federal armies, and civilian workers and contractors flocked to the city.Slavery was abolished throughout the District on April 16, 1862 — eight months before Lincoln issued the Emancipation Proclamation — with the passage of the Compensated Emancipation Act.