Pitman served as a private in the 22nd Regiment Massachusetts Volunteer Infantry, Company H. This regiment was also named the "Henry Wilson's Regiment" after Colonel and U.S. Senator Henry Wilson, who commanded the unit in 1861.
Pitman mengabdi sebagai pirabdi dalam 22nd Regiment Massachusetts Volunteer Infantry, Company H. Resimen ini juga dinamai "Henry Wilson's Regiment" setelah Kolonel Henry Wilson, yang memimpin unit ini tahun 1861.