Although many Northerners, including Abraham Lincoln, initially hoped to prosecute the war without interfering with slavery as it existed, pressure from slaves who fled to Union lines, abolitionist sentiment in the North, and a deteriorating military situation pushed Lincoln to consider abolishing slavery. In September 1862 Lincoln issued a preliminary Emancipation Proclamation. He signed the final edict on January 1, 1863. In this caricature by Baltimore pro-South Democrat Adalbert Johann Volck, an inebriated Lincoln, surrounded by symbols of Satanism and paintings honoring John Brown and slave rebellions, trod on the Constitution as he drafted the proclamation.
Source: V. Blada (A. J. Volck), Sketches from the Civil War in North America, 1861, ‘62, ’63 (1863)—American Social History Project.