The 125th Illinois Infantry was organized at Danville , Illinois .
The 125th Illinois Infantry was mustered in for three years service on September 3 , 1862 , under the command of Colonel Oscar Fitzalan Harmon .
The 125th Illinois Infantry was organized at Danville , Illinois , and mustered in for three years service on September 3 , 1862 , under the command of Colonel Oscar Fitzalan Harmon .