Civil War Union Brevet Major General. Born in Philadelphia, Pennsylvania, he was appointed as a 1st Lieutenant, 2nd United States Dragoons on June 11, 1836. First assigned to combat the Seminole Indians in Florida, he fought at the January 15, 1838 Battle of Jupiter Inlet during the First Seminole War. Promoted to Captain on December 3, 1839, he served in Florida until 1841. Sent with his regiment to Mexico when the Mexican War began in 1846, he rendered service that was commended by superiors, participating in the Battles of Cerro Gordo, Puebla, Contreras, Molino del Rey, Chapultepec and in the capture of Mexico City. After the war be received the brevet of Major, US Regular Army for "gallant conduct in the affair at Saint Augustine, August 17, 1847". He would be promoted to full-rank Major on July 23, 1850, and assigned to the 1st United States Dragoon regiment on the American Western Frontier, an arena he would spend the next ten years serving in. In April 1852 he led two companies of the 1st Dragoons and a company of the 3rd Infantry in establishing Fort Massachusetts along the Ute River near the San Luis Valley in Colorado (then part of New Mexico Territory), and later commanded the US Army post at Cantonment Burgwin in the same area, participating in actions against local Indians. In 1857 he was assigned to command the 60-dragoon escort for Lieutenant Edward Fitzgerald Beal, who had been assigned to make a wagon road survey through the Arizona Territory. The expedition was marked by Beal's use of 25 camels as pack animals. Major Blake gained a reputation during his time on the frontier as being harsh on enlistment men of his command. This treatment once resulted in him being assaulted by one of his men, Private Aaron Dwight Stevens. Private Stevens was court-martialed and sentenced to be executed, but President Franklin Piece commuted his sentence to three years' hard labor. Stevens escaped from Leavenworth prison, and became an ardent abolitionist, later being executed for his participation in John Brown's 1859 Harper's Ferry Raid. When the Civil War began, George A.H. Blake was promoted to Lieutenant Colonel, 1st United States Cavalry on May 3, 1861, and led an expedition from St. Louis, Missouri to Oregon and Washington Territory. In 1862 he was recalled to the East, and promoted to Colonel and commander of the 1st US Regular Cavalry on February 13, 1862, replacing the retired Colonel Benjamin Lloyd Beall. He would go on to lead his command during the 1862 Peninsular Campaign, fighting in the Seven Days battles and being wounded at the June 27, 1862 Battle of Gaines Mill. Named as Commissary of Musters on the staff of Major General Alfred Pleasonton in April 1863, he served in that duty until December 1863. He still saw action in the field with his unit in the cavalry actions of June 1863 that marked the beginning of the Gettysburg Campaign, fighting in the Battles of Aldie, Upperville, Middletown, and at Gettysburg. Assigned to special duty at the Cavalry Bureau in Washington, DC after the conclusion of the campaign, he performed that duty until April 1864, when he was directed to command the Union cavalry depot of Giesboro Point, Maryland. On September 1, 1864, he was assigned to special duty, serving in that role until February 1865. He spent the last days of the war as a member of a military commission in Washington, DC, assigned to that commission until March 1866. He was brevetted Brigadier General, US Regular Army on March 13, 1863 for "gallant and efficient services during the Gettysburg Campaign", and brevetted Major General, US Regular Army on the same day for "meritorious services during the war" (His Major General brevet was not commissioned at the time, and was not confirmed by the Senate until March 3, 1869). After the war he was assigned to command a regiment and post at Fort Vancouver, Washington, until his retirement by his own request on December 15, 1870. He resided in Washington, DC until his death in 1884.