Peter Klein was born in 1839 in Prussia.
Peter immigrated to America sometime before the war broke out and eventually settled in western Michigan.
He stood 5’10” with blue eyes, brown hair and a dark complexion and was a 22-year-old farmer probably living in Allegan County when he enlisted in Company C on May 13, 1861. He was reported missing in action on July 27 (probably July 21), 1861, at Bull Run, Virginia, and returned to the Regiment on July 31 at Hunter’s Farm, Virginia. Peter was discharged for consumption on September 16, 1861, at Fort Richardson, Virginia.
In 1863 he applied for a pension (no. 19155) but the certificate was never granted.
It is possible that Peter returned to Michigan where he may have reentered the service as a Private in M company, Eleventh cavalry, on August 30, 1864, at Jackson, Jackson County.