Born in York, Pa., he was a graduate of William Penn High School. Family members said that first lady Eleanor Roosevelt was the speaker at his high school graduation. He attended what is now Loyola University Maryland.
He joined the Army, served in the medical corps and was stationed in the Aleutian Islands at Dutch Harbor. He left the military as a sergeant. While stationed at Fort Holabird in Southeast Baltimore, he met his future wife, Mary E. Neunan, a Baltimore social worker and teacher.
Mr. Hackman joined Baltimore's Health Department in 1946 and worked in its housing division as education and public relations director. He worked on promoting a slum eradication effort known as the Baltimore Plan.
"It became a model for the rest of the country," said his daughter, Eileen Norton. "People from all over the country and world came here as observers. My father, who conducted tours for them, gave talks to civic and church organizations, and participated in an award-winning documentary done by the Encyclopedia Britannica."
He then worked in rent stabilization for the federal government. From 1953 until his 1984 retirement, Mr. Hackman was a salesman and manager for an advertising ink company, Sinclair and Valentine. He worked out of an office on Loch Raven Road.
A golfer, he was a longtime member of the Country Club of Maryland. He achieved a hole-in-one when he was 82 years old. He also traveled to Scotland and played the St. Andrew's course.
He enjoyed reading history and biographies, and told stories of World War II and of the interesting people he had encountered.
"He was a man of principle and integrity," his daughter said. "He was a cheerful and kind gentleman."
A Mass will be held at 1 p.m. Saturday at SS. Philip and James Roman Catholic Church, 2801 N. Charles St., where he was a member.
In addition to his daughter, survivors include a son, Mark T. Hackman of Baltimore; and three grandchildren. His wife of 59 years died in 2003.