Frederick Andrea was from Luzerne County, Pennsylvania (the family name is also recorded as Andrie, Andres, and Andreas). On April 23, 1861, Andrea mustered into service as a musician in Co. G, 8th Pennsylvania Infantry (a three-month regiment). The regiment performed guard duty along the Potomac before it was mustered out on July 29, 1861. Despite writing in his letter that he did not intend to serve longer than three months, Frederick Andrea enlisted in Co. I, 98th Pennsylvania Infantry on August 23, 1861. He was wounded at the Battle of Cold Harbor on June 3, 1864 and was discharged at the end of his three-year enlistment on September 5, 1864.