Andrew Porter, grandson of the Revolutionary General Andrew Porter and a first cousin of the mother of Mary Todd Lincoln, was born in Lancaster, Pennsylvania, July 10, 1820. He was also a first cousin of Brevet Brigadier General Horace Porter, U. S. Grant's Secretary of War and intimate friend. Andrew Porter attended West Point for six months in 1836 and at the beginning of the Mexican War was appointed a first lieutenant in the newly authorized Regiment of Mounted Riflemen. A year later he was made captain, and for gallantry in battle was brevetted major and lieutenant colonel. For the next fourteen years he did duty in Texas and the Southwest. On May 14, 1861, he became colonel of the new 16th U. S. Infantry and three days later fourth-ranking brigadier in the volunteer organization, although the appointment was not made until August 6, 1861. At the battle of First Manassas in July he commanded the 1st Brigade of Hunter's division which sustained 464 casualties; after the wounding of Hunter, Porter commanded the division itself. During McClellan's Peninsular campaign Porter was provost marshal general of the Army of the Potomac. At the close of this he was relieved from duty and that fall was ordered to Harrisburg, Pennsylvania, to aid in organizing and forwarding recruits. In October he was charged with enforcing the draft in Pennsylvania and appointed provost marshal general of the state, but on January 24, 1863, was relieved and ordered to report to the adjutant general in Washington. In July of that year he served briefly as commander of "the depot for drafted men at Philadelphia," a post from which he was relieved on July 18. Porter's health had been badly undermined by his service on the Indian frontier and his absences on sick leave were frequent; finally on April 4, 1864, he was mustered out of the volunteer service, resigning his regular commission of colonel sixteen days later. He then went abroad in order to travel for his health, making his permanent residence in Paris. He died there at his home on Rue du Colisee January 3, 1872. His remains were returned to the United States and buried in Elmwood Cemetery, Detroit. Porter's father, George Bryan Porter, territorial governor of Michigan, is also buried there, as is his father-in-law, Major John Biddle, U. S. Army, a former Philadelphian and early-day settler of Michigan.
Reference: Generals in Blue. Lives of the Union Commanders by Ezra J. Warner. Louisiana State University Press. Baton Rouge.