The 109th Pennsylvania Volunteer Infantry (aka "Curtin Light Guards") was an infantry regiment that served in the Union Army during the American Civil War.
The 109th Pennsylvania Infantry was organized at Philadelphia, Pennsylvania beginning December 1861 and mustered in for three-years service under the command of Colonel Henry J. Stainrook.
The regiment was attached to 1st Brigade, Sigel's Division, Department of the Shenandoah, to June 1862.
1st Brigade, 2nd Division, II Corps, Army of Virginia, to August 1862.
2nd Brigade, 2nd Division, II Corps, Army of Virginia, to September 1862.
2nd Brigade, 2nd Division, XII Corps, Army of the Potomac, to October 1862.
3rd Brigade, 2nd Division, XII Corps, to January 1863.
2nd Brigade, 2nd Division, XX Corps, Army of the Cumberland, to March 1865.
Guarded supply trains during the Second Battle of Bull Run.
Ringgold Gap, Taylor's Ridge, Ga.,, November 27.
Duty on Nashville & Chattanooga Railroad until April 1864.
Operations on line of Pumpkin Vine Creek and bathes about Dallas, New Hope Church, and Allatoona Hills May 25-June 5.
Ruff's Station or Smyrna Camp Ground July 4.