Bahr was born in Minneapolis to Mary Fairfax Griffith, of Warsaw, Virginia and Frederick Charles Bahr, of New York City. The family moved to Detroit in 1933.

Bahr attended Andover Prep School, and received his Bachelor's degree from Yale University, where he played football and boxed, earning him the nickname "Fearless Fred."

He married Robin Louise Renfrew of Birmingham, Michigan in 1954 and had three children. After receiving a law degree from the University Of Michigan in 1954, Bahr served in the U.S. Marine Corps and later returned to Birmingham to practice law.

He moved to the Williamsburg area in 1986 and met his second wife Jane Krieger Rhode after placing an ad in a local paper seeking a squash partner. They were married in 1990, and together raised and rescued dozens of goats, dogs, cats, and chickens.

Bahr is remembered as an unbeatable chess player and lover of history, especially the Civil and Revolutionary War eras. A lover of music, an accomplished tenor, he sang and taught his children drinking songs, including many from the Tom Lehrer canon, and a personal favorite: "They're Moving Father's Grave To Build a Sewer." He sang in several choirs including St. Peter's Episcopal Church in New Kent County, Bruton Parish Church in Williamsburg, and the Williamsburg a cappella group, "The Dukes of Gloucester."

Bahr was an active volunteer with the New Kent Literacy Program which included classes at the Henrico County correctional facilities.