Henry Larcom Abbot (August 13, 1831 - October 1, 1927) was an engineer and career officer in the United States Army. Born in Every, Massachusetts, Abbott graduated second in his class at West Point in 1854. Commissioned as a brevet second lieutenant on July 1, 1854, Abbot had initially wanted to join the Artillery, but a friend convinced him that the Engineers was a better option. By 1855, Abbot had been assigned to Lieutenant Robert Williamson's Pacific Railroad Survey in California and Oregon. Abbot also participated in several studies of the Mississippi River, including a notable study of the river's flow from the confluence with the Ohio River south to the Gulf of Mexico. Abbot was assigned to Brigadier General Irvin McDowell's forces at the outbreak of the American Civil War and was wounded at the First Battle of Bull Run. later, he served as a topographical engineer with the Army of the Potomac during the Peninsula Campaign, where he earned a brevet promotion to major at the siege of Yorktown. After the Peninsula Campaign, Abbot was transferred to command a heavy artillery unit, though that appointment did not last long as he was soon sent to Washington, D.C. to command a brigade defending the capital. In May 1864, Abbot was sent to command the artillery during the siege of Petersburg, and by December he was placed in command of all siege artillery in the Army of the Potomac and the Army of the James. After the war, Abbot remained in the army and served with the Army Corps of Engineers. He was placed in command of an engineer batallion at Willet's Point, New York, where he founded the army's Engineer Engineer School of Application, the first of its kind in the United States. After retiring from the army in 1895, Abbot continued to work as a civil engineer and was even employed as a consultant on the lock system for the Panama Canal.