Benjamin Baum was born on September 27, 1913 in Toledo, Ohio. His parents, Moses and Minnie Baum, were Russian immigrants who came to America in 1906. His father was a clothing merchant. Benjamin graduated from Union High School in Grand Rapids in 1929. He was active in drama and debating. He graduated with an Associate of Arts degree from Grand Rapids Junior College in 1931 and obtained his Bachelors of Arts degree from the University of Michigan in 1933. He then attended the Law School at the University of Michigan where he received his Juris Doctor degree in 1935. While in law school he was the associate editor of the University of Michigan Law Review.

Upon graduation he entered private practice in Milwaukee, Wisconsin. In 1939 he returned to Grand Rapids where he continued his law practice for the rest of his career. In 1941 he entered the US Army as a private and in 1946 he discharged as a captain. He spent 31 months of his service in North Africa and Italy. He was married to his wife, Anne, in 1946. They had a son and two daughters. Both he and his wife were active members of Temple Emanuel and B'nai B'rith. He was also an active member of the American Legion and the VFW and was known as an advocate for veterans rights.

In 1955, he was appointed by the Grand Rapids Community Council to chair the Grand Rapids Metropolitan Area Study. The Grand Rapids Metropolitan Area Study was an independent committee formed to analyze the needs and problems of public services in the greater Grand Rapids area. The Study was assigned to publish twelve fact finding reports that presented their analyses and recommendations for consolidation of services and potential annexation. The areas covered by the Study were the City of Grand Rapids, City of East Grand Rapids, City of Grandville, Grand Rapids Township, Paris Township, Plainfield Township, Walker Township and Wyoming Township. The Study consisted of several subcommittees with over one hundred members representing the eight areas with proportionate representation to their populations. The Study also relied on the help of several consultants and the cooperation of local governments. During 1957 and 1958 the Study published their fact finding reports. These reports drew much attention from the local press. Consolidation and annexation were highly discussed topics among city planners, public officials, and the greater community.

Benjamin Baum passed away on November 11, 1991 and is buried at Ahavas Israel Cemetery in Grand Rapids. He was known for his long legal career and for his service in the community.