During the American Civil War, soldiers were allowed to vote by mail. This was the first instance of mail-in ballots in the nation's history. At the time, of course, only men had the right to vote. In the 1862 mid-year elections, many soldiers were given leave to return home to vote. It was detrimental to the war effort, so in 1864 the Union tried a new concept: mail-in ballots. Lincoln felt this was important to his reelection because a higher proportion of Republicans enlisted. On September 27, 1864, Ulysses S. Grant wrote to the Secretary of War Edwin Stanton: The exercise of the right of suffrage by the officers and soldiers of armies is a novel thing. A very large proportion of legal voters of the United States are now either under arms in the field, or in hospitals, or otherwise engaged in the military service of the United States … they are American citizens, having still their homes and social and political ties binding them to the States and districts from which they come...