I have located the gravesite of Charles P. Markham in Helena, MT. His tombstone reads C.P. Markham, Lieut. 14th Mich. Inf.
My other sources tell me he was born abt 1840 in NY, and died 1881 in Helena, MT. Can I rely on the tombstone to be accurate? I have not been able to find a record of service. Thanks!