Antietam Generals: Truman Seymour

Truman Seymour

Born: September 24, 1824, Burlington, Vermont

Died: October 30, 1891, Florence, Italy

As a member of the famed West Point Class of 1846, Truman Seymour was in good company among Civil War commanders. Many of those in his class would join him along the banks of Antietam Creek for America’s bloodiest day on September 17, 1862. Born in 1824 to a Methodist preacher in Vermont, a young Truman Seymour attended Norwich University for two years before heading to the U.S. Military Academy. Upon graduation, Seymour became an artillery officer. He was brevetted a First Lieutenant and Captain during his service in the Mexican War, and he also saw antebellum action against Florida’s Seminole Indians in the latter 1850s. 

Brigadier General Truman Seymour

Seymour has the distinction of being one the men inside the walls of Fort Sumter when, on April 12, 1861, Confederate artillery lit up the sky over Charleston Harbor, initiating the American Civil War. Following the fort’s surrender a few days later, Seymour spent the next year aiding the effort to recruit and raise a Federal army large enough to put down the rebellion. On April 28, 1862, he was made a Brigadier General of Volunteers. Initially, he commanded a brigade in George McCall’s division of the 5th Corps; when McCall was taken prisoner at the Battle of Glendale on June 30, 1862, Seymour temporarily took over the division. During the Second Manassas Campaign, Seymour returned to his brigade command because John Reynold’s had taken command of the division, which was attached to the 3rd Corps of the Army of Virginia, under John Pope. When George McClellan went about reorganizing the Washington defenses following the abysmal Federal defeat at Second Manassas, Seymour’s brigade, along with the rest of his division and the 3rd Corps of the Army of Virginia, became the 1st Corps of the Army of the Potomac. Its new commander would be Major General Joseph Hooker.


During the Federal advance into Maryland, the 1st Corps, along with the 9th Corps, formed the right wing of the Union army. It was this wing which was used in attacks against Frosttown, Turner’s, and Fox’s Gaps during the Battle of South Mountain on September 14, 1862. During this fight, Seymour’s Pennsylvania troops distinguished themselves well, overcoming difficult and impeding terrain, driving Confederates under Robert Rhodes off of ground north of Turner’s Gap on South Mountain. By nightfall, Seymour’s brigade had played a key role in an incredibly important Federal victory.



Several days later, at Antietam, it was Seymour’s men who were first engaged against Lee’s defensive lines outside of Sharpsburg. After arriving on the eastern banks of Antietam Creek, McClellan sent the 1st Corps across the Upper Bridge at mid-afternoon on September 16. Once across the bridge, Hooker advanced his corps west so that he would be positioned north of Lee’s left flank. That evening, as Federal forces closed in on Confederate pickets and defensive lines, Seymour’s brigade came into contact with the Confederate division of John Bell Hood in the East Woods. The skirmish fire was brisk, and continued until dark, when both sides settled in to await the break of dawn, when their battle would begin in earnest.

 Carman map showing Seymour's brigade at daybreak on the 17th

When the sun rose the next morning, Seymour’s men continued their fight against the Confederate line, only now, they were engaged with part of Alexander Lawton’s division; specifically, the brigade of Isaac Trimble (led temporarily by Col. James Walker), along with the brigade of Roswell Ripley, belonging to D.H. Hill’s division. After the first half hour of fighting, Seymour’s brigade began to withdraw, as the rest of the 1st Corps was beginning its assault through the famed Cornfield. Seymour's men remained in the East Woods, or north of the East Woods for the remainder of the day. Later, when Major General Joseph Hooker was wounded, Brigadier General George Meade assumed command of the corps, leaving the division to Seymour for the time being.

 Carman map showing action between 6 and 6:30 a.m.

Seymour’s Brigade at Antietam

1st Pennsylvania Reserves: 27 casualties

2nd Pennsylvania Reserves: 34 casualties

5th Pennsylvania Reserves: 10 casualties

6th Pennsylvania Reserves: 69 casualties

13th Pennsylvania Reserves: 25 casualties

Total: 155 casualties


George Meade’s Division at Antietam:

2855 Present (Source: Ezra Carmen, The Maryland Campaign of 1862: Volume 2, Antietam, ed. Tom Clemens), 573 casualties (20% casualties)


For his actions at South Mountain and Sharpsburg, Seymour was brevetted first a Lieutenant Colonel and then a full Colonel in the regular army (a distinction existed between a rank in the volunteer army and the regular army; thus, by being brevetted a Colonel in the regular army, Seymour was promoted in rank, despite holding an appointment as a Brigadier General of Volunteers)


Following Antietam, Seymour was sent south once again to Charleston Harbor. There, on July 18, 1863, he oversaw the famed attack against Fort Wagner, where the legendary 54th Massachusetts led the way and suffered near 50% casualties, including their colonel, Robert Gould Shaw (Captain, 2nd Massachusetts at Antietam), who was killed that day. During this assault Seymour was wounded, but he would survive. Later that year, he commanded troops at the Battle of Olustee, the biggest Civil War battle to be fought in the state of Florida.


In May of 1864, Seymour came back to the Eastern Theater of the war. He was captured at the Battle of the Wilderness, and then part of a prisoner exchange that August. Following his exchange he again became a division commander and saw action in the Shenandoah, at Petersburg, and at Appomattox. At the end of the war, he was brevetted a Major General in both the regular and volunteer armies. In 1866, he was given command of the 5th U.S. Artillery, which he held until 1876, when he retired and left the United States. Seymour lived out his remaining days in Florence, Italy, until he died in 1891. While he was buried in Italy, his wife lived on until 1919 when she passed away and was interred at West Point.

Dan Vermilya

Park Ranger