Although President Abraham Lincoln was renowned for abolishing slavery, his main goal was to preserve the Union. In response to an open letter by Horace Greeley, the New York Tribune editor, Lincoln wrote: "My paramount object in this struggle is to save the Union, and is not either to save or destroy slavery."
As the American Civil War raged on between the North and South, President Lincoln decided that abolishing slavery was the best recourse for winning the war and preserving the Union. The victory of the Union forces against the Confederate army in the Battle of Antietam was pivotal to the enactment of Lincoln's Emancipation Proclamation. Afterward, the War for Union also became the War for Freedom.