He was the son of a South Carolina slavewoner who had moved his family to Indiana after he freed his slaves. At the age of 19, young Burnside was appointed to the West Point. He graduated in 1847, ranked 18 out of 38 in his class, and was commissioned a second lieutenant in the 2nd U.S. Artillery.
He was in the the Mexican War, and then was detailed for duty against the Apaches in the New Mexico Territory, and served some 2 years in frontier warfare. In 1849, he was wounded by an arrow in his neck in Las Vegas, New Mexico. In 1852, he was appointed to the command of Fort Adams in Newport, Rhode Island. While there, he married Mary Bishop of Providence.
In 1853, he resigned his commission in the Regular Army, although maintaining a position in the state militia, and devoted his time and energy to the manufacture of the famous rifle that he designed, the Burnside Breechloading Carbine. The U.S. government contracted with the Burnside Arms Company to equip a large portion of the army with his carbine, and induced him to establish extensive factories for its manufacture. They produced more than 55,000 rifles for the US Army. The works were no sooner complete than another gunmaker bribed Secretary of War John Floyd to break his contract with him, who was ruined. He went west in search of employment and became treasurer of the Illinois Central Railroad, where he worked with George B. McClellan.
At the outbreak of the Civil War, Burnside was a Brigadier General in the Rhode Island Militia. He raised a regiment, the 1st Rhode Island, and was appointed its Colonel on May 2, 1861. Within a month, he ascended to brigade command in the Department of Northeast Virginia. He commanded the brigade at the 1st Bull Run and was promoted to Brigadier General.
Burnside commanded the North Carolina Expeditionary Corps, which formed the nucleus for his future IX Corps, and the Department of North Carolina, from September. For his successes at the battles of Roanoke Island, New Berne, Beaufort and Fort Macon, He was promoted to major general for the capture of Fort Macon. In July, his forces were transported north to Newport News, Virginia, and became the IX Corps of the Army of the Potomac.
Following McClellan's failure in the Peninsula Campaign, he was offered command of the Army of the Potomac. Refusing this opportunity, in part due to his loyalty to McClellan (and also because he understood his own lack of military experience), he detached part of his corps in support of Major Gen. John Pope's Army of Virginia in the Northern Virginia Campaign. Again offered command following the debacle at 2nd Bull Run in that campaign, he again declined.
Burnside was given command of the “Right Wing” of the Army of the Potomac (the I and IX Corps) during the Maryland Campaign. He fought at South Mountain and then at Antietam, where his 2 corps were placed on opposite ends of the Union battle line. He nonetheless remained in wing command over the IX Corps—a cumbersome arrangement that may explain his slowness in attacking and crossing what is now called "Burnside Bridge". The delay allowed Lieutenant Gen. A.P. Hill's Confederate division to come up from Harpers Ferry and repulse the Union breakthrough.
McClellan was removed after failing to pursue Gen. Robert E. Lee's retreat from Antietam and he was assigned to command the Army of the Potomac. He reluctantly obeyed this order.
President Abraham Lincoln pressured Burnside to take aggressive action and on November 14, 1862, approved his plan to capture the Confederate capital at Richmond, Virginia. This plan led to a humiliating and costly Union defeat at Fredericksburg. His lack of resolution led to his losing the battle, in addition to disappointing Lincoln and injuring the army's morale. Accepting full blame for the loss, he offered to retire from the army, but this was refused.
In January 1863, in an attempt to make up for the defeat at Fredericksburg, Burnside decided to cross the Rappahannock River and attack the Confederates from behind. As the troops began moving, it began raining heavily, with strong winds. By the end of the day, the march across the river was a muddy, disorganized mess, which was later called Burnside's "Mud March." In its wake, he asked that several officers be relieved of duty and court-martialed and he also offered to resign. Lincoln accepted his resignation, and on January 26, replaced him with Mal. Gen. Joseph Hooker.
Lincoln was unwilling to lose Burnside from the army and assigned him to command the Department of the Ohio and the IX Corps. There, he presided over the arrest and military trial of former Congressman Clement L. Vallandigham for sedition, as well as the arrests and trials of captured Confederate cavalryman Brigadier Gen. John Hunt Morgan and some of his men.
He advanced to Knoxville, Tennessee, but after the Union defeat at Chickamauga, he found the tables turned and he was besieged in Knoxville by Lieutenant Gen. James Longstreet. After Gen. Braxton Bragg's defeat by Gen. Ulysses S. Grant at Chattanooga, troops under Major Gen. William T. Sherman marched to his aid and lifted the siege.
Burnside was then ordered to take the IX Corps back to Virginia, where he fought in the Overland Campaign directly under Grant; his corps was not assigned initially to the Army of the Potomac because he outranked its commander, Major Gen. George G. Meade. This arrangement was rectified during the battle of North Anna when he agreed to waive his precedence of rank and was placed under Meade's direct command.
Burnside fought at the Wilderness, Spotsylvania Court House, Totopotomoy Creek, and Bethesda Church, where he performed in a mediocre manner, appearing reluctant to commit his troops to frontal assaults after the Fredericksburg experience. After Cold Harbor, he took his place in the siege lines at Petersburg in July 1864.
At Petersburg, Burnside agreed to a plan of digging a mine under a fort in the Confederate entrenchments at Petersburg and ignite explosives there. The fort was destroyed in what is known as the battle of The Crater. He received the blame for this fiasco and was sent on leave. He was never recalled back to duty. He finally resigned his commission on April 15, 1865.
After his resignation, Burnside was employed in numerous railroad and industrial directorships, including the presidencies of the Cincinnati & Martinsville Railroad, the Indianapolis & Vincennes Railroad, and the Rhode Locomotive Works. He was elected to 3 one-year terms as Governor of Rhode Island from 1866–1868. He was President of the Veterans' Association, the Grand Army of the Republic. The National Rifle Association chose him as their first president at its inception in 1871.
During a visit to Europe in 1870, Burnside attempted to mediate between the French and the Germans in the Franco-Prussian War. In 1874, he was elected a U.S. Senator from Rhode Island and served until his death. He is buried in Swan Point Centary at Providence. Another of his legacies is the term "sideburns," which originated from his peculiar whiskers, joining his ears to his mustache, but with chin clean-shaven.
Brigadier General USV- August 6, 1861
Major General USV- March 18, 1862
Colonel, Ist Rhode Island (May 2, 1861)
2nd Brigade, 2nd Division, Army of Northeastern Virginia (June-July 1861)
North Carolina Expeditionary Corps (December 1861 - April 1862)
Department of North Carolina (January 13 - July 10, 1862)
IX Corps, Army of the Potomac (July 22 - September 3, 1862, March 17-19, 1863, and April 13-August 14, 1864)
Left Wing, Army of the Potomac (September 1862)
Army of the Potomac (November 9, 1862 - January 26, 1863)
Department of the Ohio (March 25 -December 11, 1863)