The 1st Massachusetts was a volunteer infantry regiment that served in the American Civil War. Formed in 1861, it was one of the first regiments to respond to President Abraham Lincoln's call for troops. The regiment participated in several key battles, including the Battle of Antietam and the Battle of Gettysburg, contributing to the Union's efforts. Throughout its service, the 1st Massachusetts was known for its bravery and discipline. The regiment was mustered out in 1864 after enduring significant casualties and hardships. Its legacy is remembered as part of Massachusetts' rich military history during the Civil War.