He later moved to the artillery, in which branch he served at the battles of Trenton, Princeton, Brandywine, Germantown, and Tioga Point.

He was later directed by General George Washington to supervise the preparation of artillery ammunition for the Siege of Yorktown.

[2] After the end of the war, Porter continued to serve in a military role with the Pennsylvania militia, rising to the rank of major general.

He also served as the state's surveyor-general, and was one of the commissioners tasked with determining the boundaries between Pennsylvania, Virginia, and Ohio.

[9][10] His grandson through his son George was Andrew Porter (1820–1872), also a brigadier general in the Union during the American Civil War who was an important staff officer under George B. McClellan during the 1862 Peninsula Campaign, serving as the Provost Marshal of the Army of the Potomac.