Harry Hughes was born in Easton on November 13, 1926, and grew up in Denton. He attended Mercersberg Academy in Pennsylvania and Mt. St. Mary's College. During WW II, he enlisted with the U.S. Navy Air Corps and later entered the University of Maryland where he earned his B.A. degree in 1949. He received his law degree from George Washington University School of Law in 1952.
He was elected to the House of Delegates from Caroline County in 1954, and in 1958, was elected to the State Senate. He served in the Senate for three terms and held various leadership positions, including Majority Leader and Chairman of the Finance Committee. From 1971-79, Hughes was Secretary of the Department of Transportation, when he resigned over a disagreement over the award of a construction contract for the Baltimore subway. In 1978, he defeated Acting Governor Blair Lee III to become governor.
During his two terms in office, efforts to clean up the Chesapeake Bay were initiated, careful attention was given to fiscal issues, and foreign trade initiatives with China were begun. Maryland celebrated the 350th Anniversary of its founding in 1984, as well as the 200th anniversaries of two significant events that took place in the State House: George Washington's resignation as Commander-in-Chief, and the Ratification of the Treaty of Paris that ended the American Revolution. To better preserve the history of the State a new State Archives was opened in September 1986. The Savings & Loan crisis occupied much of the last months of the Hughes' Administration and saw the implementation of a plan in which all insured depositors recovered their investments.
Harry Hughes married Patricia Donoho on June 30, 1951. They have two daughters: Ann and Elizabeth.