Born in Black Rock in Erie County, (now a neighborhood in Buffalo), Peter A. Porter was the son of Peter Buell Porter and Letitia Breckinridge. He graduated from Harvard College in 1845, later going to Germany where he studied at the universities of Heidelberg and Breslau until 1849.

On his return to the United States and until the beginning of the Civil War, Porter took an active part in the business and social life of Niagara Falls.

He was married March 30, 1852 in North Carolina, to Mary "Polly" Cabell Preston Breckenridge. They had son, Peter A. Porter.

Mary died in 1854, and in November 1859, Col. Porter married Josephine M. Morris, daughter of George Morris. Their children were Laetitia H. Porter and George M. Porter.

In 1861, while a member of the New York Legislature, and was nominated for Secretary of State.

Instead, he raised a regiment, the 129th New York Volunteer Infantry.

In 1863 it became the 8th New York Heavy Artillery, of which he was commissioned Colonel.

At his request he was sent with his troops to the front in 1864, the regiment being incorporated with the Army of the Potomac under General Grant.

Porter took part in all the battles of the Wilderness campaign, and Cold Harbor, where he was shot six times while leading his regiment up to the rebel entrenchments. For two days Col. Porter's body lay in front of the enemy's works, and could not be recovered. On the second night, five brave soldiers of his command bore back his remains to the Union lines.

He was brought home and rests near one of the soldiers who recovered his body LeRoy Williams.