Porter, Fitz-John (1822–1901), a United States army officer. Porter, a Union major general, was involved in a celebrated controversy during the Civil War. At the Second Battle of Bull Run, 1862, he was under the command of Major General John Pope, an officer whose competency he had openly criticized. After the battle, Porter was accused by Pope of disobeying orders to attack Confederate forces under Stonewall Jackson, and thus contributing to the Union defeat. Porter was court-martialed and dismissed from the army. He succeeded in getting his case reviewed and in 1886 won a reversal. The review board held that his career had been ruined for failing to carry out orders that under the conditions of battle were ill-advised. He was restored to his permanent rank of colonel, and then retired.

Porter was born in Portsmouth, New Hampshire. He graduated from West Point in 1845 and served in the Mexican War. Early in the Civil War, he ably commanded a corps in General George B. McClellan's Peninsular Campaign. After leaving the army, he held various posts, including fire, police, and then public works commissioner of New York City.