Battery A was organized Peoria, Illinois and mustered in May 23, 1861 for state service under the command of Captain Peter Davidson.
The battery was attached to Fremont's Army of the West and to Department of the Missouri to February 1862.
Artillery, 3rd Division, Army of Southwest Missouri, to July 1862.
Artillery, 14th Division, XIII Corps, Army of the Tennessee, to July 1863.
Artillery, 1st Division, XIII Corps, Department of the Gulf, to June 1864.
Battery A, 2nd Illinois Light Artillery mustered out of service July 28, 1865.
Ordered to Milliken's Bend, Louisiana, March 20, and duty there until April.
Duty in District of LaFourche and defenses of New Orleans, Louisiana, until August 1864.
Operations in Mobile Bay against Forts Gaines and Morgan August 2–23.
Duty in the defenses of New Orleans and District of LaFourche till July 1865.
Expedition over Boston Mountains to Van Buren, Arkansas, December 27–29.