President Abraham Lincoln (1809-1865), 16th President of the United States until his assassination on April 14, 1865, by John Wilkes Booth, signed the Emancipation Proclamation on January 1, 1863. Issued as an executive order based on his powers as commander-in-chief, the proclamation declared that all slaves in rebellious states were free. This was a major blow to the Confederacy and transformed the American Civil War into a conflict to end the institution of slavery. This copy of the Emancipation Proclamation is one of the 26 known copies of the Leland-Boker edition. This "authorized edition" was created in June 1864 for sale at the Great Central Fair of the United States Sanitary Commission in Philadelphia as a fundraiser to help sick and wounded Union soldiers. It was the idea of two Union League members, Charles Godfrey Leland and George Boker. Forty-eight copies were printed and signed by Abraham Lincoln, Secretary of State William H. Seward and the President's private secretary John G. Nicolay. Each document sold for $10.