Bowman served from 1775–1783 as a Private, then Lieutenant in the 1st Battalion Lancaster County Militia under the command of Captain Edmond Lintner.
He died before May 18, 1816, when his will was probated in North Huntington Township, Westmoreland County, at the age of 72. Catherine died after October 5, 1814, when his will was made, as she was named in the will. They are believed to be buried in the Harrold Zion Lutheran Cemetery next to Harrold’s Reformed Church in Hempfield Township, Westmoreland County, Pennsylvania, at the rear of the church on the east side marked by an old stone headstone and a Revolutionary War marker. Few people visit that old area now, but there still those that remember his service. Sixteen people have honored Bowman by claiming him as their Patriot, their Revolutionary War ancestor. He will always be remembered now as Iowa’s representative of the DAR on the Schuylkill River Trail connecting Philadelphia to Valley Forge on the DAR Pathway of the Patriots.