The United States has a long history of electing veterans as president. In fact, the majority of U.S. presidents have served in the military. Of those, seven were in the Union Army during the Civil War. Three are particularly noteworthy.

The Most Famous Civil War Veteran in the White House

Ulysses S. Grant's successes as a Union general brought him wide attention even during the war. He commanded major victories at the Battle of Shiloh and the Battle of Vicksburg. In 1864, President Abraham Lincoln, who had turned to Grant when he needed someone reliable, made him General-in-Chief of all Union armies. Grant served two terms as president, beginning in 1868.

The Battle-Scarred President

Though he had no prior experience in the military, Rutherford B. Hayes began the war as a major and ended it as a breveted major general -- a temporary rank bestowed for distinguished service. Wounded five times in battle, he gained the respect of men he commanded and his superiors by his fierceness. Hayes served one term from 1877 to 1881.

The Last Civil War Veteran in the White House

William McKinley was the final Civil War veteran elected president. He served in the Union Army on the staff of president-to-be Colonel Rutherford B. Hayes as a second lieutenant. Having begun the war as a private, McKinley proved himself a brave soldier, fighting at Antietam -- one of the bloodiest battles of the war. McKinley began his first term as president in 1897. He was elected again in 1900; however, his second term ended prematurely when was assassinated in 1901.