Dennis Crater enlisted with the 7th New Jersey Volunteers, Company H on July 8, 1862 for a 3 year enlistment. He was 44 years old. According to records, he was wounded at the Battle of Spottsylvania, Virginia, and was discharged from The Ward Army Hospital in Newark on October 20, 1864. He did return to duty, and continued in the war until its conclusion. He was mustered out on May 3, 1865.

He passed away at aged 68, on October 30, 1886. He is buried in Pleasant Hill Cemetery in Chester, New Jersey.