Jim Mullen was born in October of 1935 in Philadelphia, Pennsylvania. He grew up in Northeast Philadelphia alongside his two brothers and went to Northeast Catholic High School. During this time, he enjoyed playing sports with his friends, reading books such as Sherlock Holmes, and playing the saxophone in his school band. After high school, he decided to commute to Villanova University, which required trolley rides, train rides, and car rides from friends until he eventually got his own car. He took the LSAT while in college and received a score that got him a scholarship for Villanova Law School. He lived on campus and although it was hard, he enjoyed his law school experience. He graduated from Villanova Law School in 1960.

After graduation, Jim decided to look for work in New Jersey because that is where his family had moved to. He took a bar review course and passed the bar exam on his first try, becoming a New Jersey attorney. He got hired at a law firm in Camden where he did trail work. He liked working with other attorneys and he was happy with his successful career. He became a partner of the firm until it dissolved in 1998. He then went into private practice until 2015 when he decided to retire.

In 1963, Jim married Judith, a legal secretary he had met at a Christmas party. The couple have been married for almost 60 years and have had four children together: Jenny, Jim, Thomas, and Terry. Jenny, Thomas, and Terry followed in their father’s footsteps and became lawyers themselves. Jim and Judith enjoy traveling together, and they have visited multiple battlefields on their trips.

He became interested in the Civil War during high school when he read a series of books about the war written by Bruce Catton. His father was also interested in the topic. Jim would talk with his friends about the war and travel to related historical sites in his youth. He joined the Old Baldy Civil War Round Table with his friend while it was still located in Philadelphia. He loved traveling with the Old Baldy CWRT to visit the battlefield at Antietam. Besides the Civil War, he enjoys reading about local and country-wide politics.