Ambrose Everts Burnside was born in Liberty, Indiana, the fourth of nine children. His parents, Edghill Burnside and Pamela Brown Burnside, were of Scots-Irish descent. His early life on the Indiana frontier instilled in him a strong work ethic and a practical approach to problem-solving, traits that would later define his diverse career.

Despite initially planning to become a tailor, Burnside received an appointment to the United States Military Academy at West Point. While not a stellar student (he graduated 18th out of 38 in his class), he excelled in practical skills and made valuable connections. His West Point education laid the foundation for his future military career.

Burnside received a brevet promotion to second lieutenant and served in the Mexican-American War, though he did not see active combat. His wartime experience, while limited, exposed him to the realities of military life and further honed his engineering skills, which he applied to bridge construction.

After the Mexican-American War, Burnside served on the Western frontier. This period saw him engaged in skirmishes with Native American tribes and allowed him to further develop his leadership skills in a challenging environment. He was later promoted to First Lieutenant.

Resigning from the army in 1853, Burnside dedicated himself to his invention, the Burnside carbine, a breech-loading rifle. He established the Burnside Arms Company in Bristol, Rhode Island. Despite being a superior weapon, government contracts proved elusive and the company eventually failed financially, leaving Burnside deeply in debt. Although a business failure, the Burnside carbine would later be widely used during the Civil War.

At the outbreak of the Civil War, Burnside volunteered his services and was appointed Colonel of the 1st Rhode Island Volunteers. He quickly distinguished himself in several early battles, notably leading a successful expedition to capture Roanoke Island and New Bern, North Carolina. These victories earned him promotion to Major General and national recognition.

Following the Battle of Antietam, Burnside reluctantly accepted command of the Army of the Potomac after McClellan's removal. This was despite his reservations about his ability to handle such a large and important command. His leadership at the disastrous Battle of Fredericksburg in December 1862, marked by a frontal assault against entrenched Confederate positions, resulted in heavy Union casualties and severely damaged his reputation as a military leader.

During the Siege of Petersburg, Burnside commanded the IX Corps. He conceived the plan to detonate a mine beneath Confederate lines, creating a large crater. However, poor execution after the explosion, including a chaotic and ill-prepared Union assault into the crater, resulted in another Union defeat and further tarnished Burnside's military record. He was subsequently relieved of command.

Despite his military setbacks, Burnside remained popular in Rhode Island due to his pre-war business endeavors and his connection to the state's volunteer regiments. He was elected Governor of Rhode Island in 1866, a position he held for three consecutive terms. As governor, he focused on economic development and veterans' affairs.

Following his governorship, Burnside was elected to the United States Senate in 1875. He served as a Senator until his death, focusing on military affairs and advocating for veterans' benefits. His senatorial career marked a period of relative stability and public service after the tumultuous years of the Civil War.

Ambrose Burnside died suddenly of 'neuralgia of the heart' (likely angina) at his home in Bristol, Rhode Island, on September 13, 1881. He was given a hero's funeral and remembered for his contributions to Rhode Island and his long, if controversial, military career. His legacy remains complex, a mixture of innovation, public service, and military failure.