Colonel Peter Clarkson Ellmaker (August 11, 1813 –October 12, 1890)[1] was an officer in the United States and Union armies, before, during and after the American Civil War.

[4][1] In 1830, he volunteered in the local fire department, and was elected chief marshal for a military and civic parade held in honor of General Lafayette in 1832.

[3] The Grays were called to Harrisburg by Governor Joseph Ritner to assist in preserving the peace when the Pennsylvania legislature was under threat by a mob.

[3] While the Washington Grays left the city to serve on the front lines, Ellmaker and others decided to form a company of home guards to protect Philadelphia.

[1] Recruiting began in August 5, and by the end of the month, the 119th Pennsylvania Volunteers were called to help defend Washington, arriving with 800 men; Ellmaker was again elected colonel.

[1] In October, the regiment joined the Army of the Potomac, as part of the First Brigade, Second Division, Sixth Corps, near the battlefield at Antietam.

[1] Ellmaker was in command of the brigade at the Second Battle of Rappahannock Station, and led his men in a "daring" charge under artillery and musket fire on November 7, 1863.

[1] On January 12, 1864, Colonel Ellmaker resigned his command due to persistent rheumatism and a pending lawsuit against his family.