Abraham Newcomer was likely born in Norristown, Pennsylvania in 1835 to parents, John and Elizabeth Newcomer.

Abraham married Almira Young on August 18, 1861 in Philadelphia.

He went on to server as a Private in the 138th Pennsylvania Volunteer Regiment, Company A.  He mustered in at Harrisburg on August 19, 1862.  He would be discharged from the military based on a surgeon's certificate on August 25, 1863.  He died later that year, on December 5, 1863 and buried a few days later on a plot at Historic Montgomery Cemetery that was purchased by his father, John Newcomer.  His tombstone reads at the top, "My Darling Husband".

His wife Almira Newcomer filed a petition for benefits in early 1864.