Who was the first President of America to assassinate while in office?

Abraham Lincoln was the first U.S. president to be assassinated while serving, after he was shot by John Wilkes Booth, who was a renowned actor who supported the Confederates, on April 14, 1865. The shooting took place at Ford's Theatre in the U.S. capital, Washington D.C., just five days after Confederate General Lee had given in to General Ulysses S. Grant. Booth had shot Lincoln with the intention of completely destabilizing the government of the Union. Although he was not the first U.S. president to be killed while in office, he was the first to be murdered.