Lincoln administration authorizes Union soldiers to cast mail ballots in 1864 presidential election

The Lincoln administration, working with Union-controlled state legislatures, authorized soldiers serving in the field to cast absentee ballots in the 1864 presidential election. Roughly 150,000 Union troops voted by mail from active duty positions. Lincoln won the military vote decisively, with soldiers choosing to continue the war rather than accept the Democratic peace platform. This was the first large-scale use of mail-in voting in American history.