The 105th Pennsylvania Infantry was founded by Amor McKnight, a lawyer and resident of Brookville, Pennsylvania who became one of the state's earliest responders to President Abraham Lincoln's call for volunteers to defend Washington, D.C. following the fall of Fort Sumter to Confederate States Army troops in mid-April 1861. After honorably completing his three months' service as captain of Company I with the 8th Pennsylvania Infantry and honorably mustering out on July 29, 1861, McKnight was then authorized by the state in early August to raise a new regiment. Recruiting for the 105th Pennsylvania then began and was completed that same month. Nicknamed the "Wildcat Regiment" in recognition of the unit's large membership from the Wildcat Congressional District in Jefferson, the 105th Pennsylvania was also staffed by a large contingent of men from Clarion County. Commissioned as a colonel, McKnight was placed in charge of the regiment after its men mustered in at Pittsburgh on September 9, 1861. Serving under him as field and staff officers were: W. W. Corbett, lieutenant colonel, and M. M. Dick, major.