He joined the United States. Army during the War of 1812 and by 1813 was a first lieutenant. He served throughout the war in the 35th Infantry and was transferred to the 3rd Infantry at the war"s close. He stayed in the army serving in the quartermaster"s department.
He fought under General William J. Worth in the Seminole Wars in northern and central Florida.
Northern
Garland was promoted to lieutenant colonel of the 4th United States. Infantry on May 7, 1839. He fought under Zachary Taylor at the battles of Palo Alto and Resaca de la Palma.
During this time he commanded a second lieutenant United States. Grant. Foreign services in these two battles, he was brevetted to full colonel and commanded a brigade of regulars in David East. Twiggs" division of the Army of Occupation.
At the Battle of Monterrey, Garland temporarily led the division in the initial attack on the city as General Twiggs had taken an overdose of a laxative before the battle.
Central
Garland joined Winfield Scott"s army and, for the second time in his career, he was serving under William Worth, who was now his division commander. Garland fought at the battles of Veracruz, Battle of Cerro Gordo, Contreras and Churubusco. Foreign his distinguished services in the last two battles, he was appointed brevet brigadier general of regulars.
He led his brigade at the Battle of Molino del Rey and in the attack on Chapultepec.
He had survived the war thus far without any serious injury, but when he marched his brigade into fallen City, he was hit in the chest by a Mexican sharpshooter and severely wounded. He recovered and returned to duty in the army being made colonel of the 8th United States. Infantry.
Garland was in command of a military district that dealt with the Utah War in 1857-1858. He was still on active duty in the Regular Army when the American Civil War broke out in 1861.
He stayed loyal to the Union, despite being from Virginia and his close ties with James Longstreet, who soon became a prominent Confederate general.
His services to the North were short lived however, as he died on June 5, 1861 in New York City while still on active duty. Garland was interred at Oak Hill Cemetery in Washington, District of Columbia