Albert Sidney Johnston was born in Washington, Kentucky, on February 2, 1803. After attending Transylvania University in Lexington, Johnston was appointed to the United States Military Academy at West Point in 1822. He graduated in 1826, finishing eighth in his class of 41.

Johnston was commissioned in the U.S. Army as a brevet second lieutenant and spent time in New York and Missouri before serving during the Black Hawk War (1832), a brief conflict between United States militia units and a band of Sauk, Meskwaki and Kickapoo Native Americans. Johnston had married his first wife, Henrietta Preston, in 1829, and in 1834 he resigned from the military to care for her until her death from tuberculosis in 1836.

Johnston moved to the new republic of Texas in 1836 and enlisted as a private in its army during the Texas Revolution (1835-36). Johnston swiftly rose to the rank of senior brigadier general, replacing General Felix Huston in January 1837. A quarrel over the position led to a duel between the two officers in which Johnston was wounded in the hip. Johnston would later serve as secretary of war in the Republic of Texas from 1838 to 1840.

Johnston resigned in 1840 and returned to his home state of Kentucky. In 1843 he married Eliza Griffin, the cousin of his first wife, and settled in Galveston, Texas. He later served as a colonel of Texas volunteers during the Mexican-American War (1846-48) and was cited for bravery during the Battle of Monterrey. After the admission of Texas to the United States, Johnston was reappointed as a major in the U.S. Army and served as a paymaster. He was later promoted to colonel in the 2nd U.S. Cavalry and led operations against the Comanche on the Texas frontier.

In 1856 Johnston led a U.S. military force to confront Brigham Young and his Mormon followers, who had clashed with the United States over governance of the Utah Territory. The resulting intervention—known as the Utah War (1857-58)—avoided bloodshed and succeeded in removing Young as governor of the territory. Johnston was promoted to brevet brigadier general in 1857, and in December 1860 he was transferred to California, where he commanded the Department of the Pacific.

Johnston resigned from the U.S. Army in May 1861 after his adopted state of Texas seceded from the Union. As a former U.S. Army general, the 58-year-old Johnston was considered one of the South’s senior officers. He was highly respected by Confederate President Jefferson Davis, a former classmate at West Point, and became one of only eight Confederate officers to receive the rank of full general. Johnston was placed in command of Confederate Department No. 2, which encompassed a vast swath of the South from the Appalachian Mountains to Texas and included jurisdiction over the Civil War’s Western Theater.

Johnston was considered by many of his contemporaries to be the finest soldier on either side of the conflict, but his early performance in the Civil War drew some criticisms. Although he was initially successful in raising an army and positioning it against a much larger Union force, Johnston’s thin defensive line in Kentucky was soon broken in February 1862. Following Union general Ulysses S. Grant’s capture of Fort Henry and Fort Donelson—two vital Confederate strongholds on the Tennessee and Cumberland rivers—Johnston was forced to effectively abandon Kentucky and Tennessee and fall back into the Deep South.

Johnston concentrated his army around the rail junction at Corinth, Mississippi, where he rendezvoused with the forces of his subordinate P.G.T. Beauregard. Meanwhile, Ulysses S. Grant’s army moved further south via the Tennessee River with the intention of capturing the vital Memphis and Charleston Railroad. Recognizing an opportunity to catch the Union forces by surprise, Johnston executed a massive offensive near Pittsburg Landing, Tennessee, on April 6, 1862. In the ensuing engagement at the Battle of Shiloh, Johnston’s 45,000 Confederates made early gains, collapsing Grant’s front lines and pushing his army north toward the Tennessee River with a series of bold charges.

Recognizing that his inexperienced troops would be hesitant to fight, Johnston elected to lead one of the later offensives himself. During a charge on the afternoon of April 6 he was wounded in the back of the knee—possibly by his own men. The bullet struck an artery, and Johnston bled to death before he could receive medical attention. It was later speculated that nerve damage from his old dueling wound prevented Johnston from recognizing the severity of his injury until it was too late. Beauregard would take over as commanding officer for the remainder of the Battle of Shiloh, the bloodiest engagement of the war up to that point. His decision to delay further attacks until the next day allowed Grant’s army to gain reinforcements and turn the tide of the battle with a counterattack, securing a Union victory.

Johnston’s death at the age of 59 was seen as a major blow to the Confederacy. By the end of the war in 1865, he remained the highest-ranking officer on either side to have been killed in action.