[5] After a few years in a government job with the United States Coast Survey[7] in Washington, D.C., he returned to Jefferson County as a farmer in 1855.

[10] George Porterfield initially was appointed colonel and inspector general of militia at Harpers Ferry, Virginia.

Porterfield was expected to hold and protect both the main line and the Parkersburg branch of the Baltimore and Ohio Railroad at that location.

[14] He found that the townspeople, being mostly Irish railroad workers,[15] mainly supported the Union and that the pro-Union Grafton Guards militia company occupied the town.

Porterfield was able to intercept Federal telegraph messages with local support, and reported to Lee that companies were being organized in Clarksburg, Pruntytown, Philippi, Weston, and Fairmont, but that only two were armed, and one had only "old flint-lock muskets, in bad order, and no amumnition...".

[19] He advised authorities in Richmond that they would need to send a large force to hold the area for the state, but the leaders in Richmond, including General Lee, were unwilling to send soldiers from the eastern part of the state to the western counties at that time for reasons that included not irritating Union sympathizers in the area.

Porterfield then decided that he could not capture or even raid Wheeling, Virginia, for supplies as desired by Governor Letcher[22] and that his position at Grafton was threatened.

[23] In order to prevent the advance of Union forces, Porterfield decided to burn two bridges on the Baltimore and Ohio Railroad between Farmington and Mannington, West Virginia.

[28] On May 28, Porterfield withdrew his force to Philippi, strongly secessionist in sentiment,[29] in Barbour County about 30 miles (48 km) to the south of Grafton.

Also on May 28, McClellan placed the entire Union force in western Virginia, about 3,000 men, under the command of Brigadier General Thomas A. Morris.

[33] At about dawn on June 3, 1861, the larger Union force surprised the Confederates under Porterfield's command who were mostly still asleep in their tents in their camp just outside Philippi.

[4] The Confederates had few poorly positioned pickets on duty on the rainy night of June 2–3 and the Union force was able to approach close to the camp until being discovered because of the premature firing of firearms.

Porterfield and those of his men who were not dispersed or captured reorganized down the road and retreated to Beverly, Virginia, about 30 miles (48 km) to the south.

[40] Porterfield was replaced in command of the Confederate forces in western Virginia by Brigadier General Robert S. Garnett on June 13, 1861, ten days after the battle.

[5] In 1871, George Porterfield became one of the founders of the Bank of Charles Town in Jefferson County, West Virginia, which he served for many years as cashier.