John H. Briscoe in Annapolis on Jan. 27, 1977. (Harry Naltchayan/THE WASHINGTON POST)

John Hanson Briscoe, a retired St. Mary’s County Circuit Court judge and former speaker of the Maryland House of Delegates who made historic and environmental preservation central tenets of his career, died Jan. 1 at his home in Hollywood, Md. He was 79.

The cause was cancer, said his son, John H. Briscoe Jr.

Judge Briscoe was a member of one of the state’s oldest families, whose roots in St. Mary’s County date to the 17th century. He was a direct descendant of John Hanson, the first president of Congress under the Articles of Confederation. Judge Briscoe’s great-grandfather owned the Sotterley Plantation, a 1703 estate and National Historic Landmark in Hollywood.

Judge Briscoe spent much of his early career in politics. In 1962, he was a member of Maryland Sen. J. Frank Raley Jr.’s Democratic reform ticket of candidates who ousted the Dorsey family political machine that had run St. Mary’s County politics for 25 years.

Judge Briscoe was elected to the Maryland House of Delegates and served as the chairman of several committees, including Environmental Matters and Ways and Means, before being elected speaker in 1973. It had been 109 years since St. Mary’s County produced a House speaker, according to the Enterprise, a Southern Maryland newspaper.

In the legislature, he helped oversee the expansion of Point Lookout State Park in Scotland, Md., and the preservation of St. Clements Island, where the English settlers who established the colony of Maryland first landed in 1634. He also helped establish Greenwell State Park in Hollywood and the College of Southern Maryland in La Plata.

As House speaker, he was known for his “powers of persuasion and mediation” and for leading the House with a “sharp wit and a stern hand,” according to a 1978 Washington Post article on his tenure. He was instrumental in ushering in property tax reform and state civil rights laws and developed a reputation for being firm but fair.

“I am a great believer in getting things done by convincing people of the wisdom of it rather than by asserting power,” he told The Post after his election in 1973.

After leaving the speakership and the House in 1979, he concentrated on his private law practice in Lexington Park until he was appointed circuit court judge in 1986. He retired in 2002.

John Hanson Briscoe was born April 10, 1934, in Leonardtown, where he graduated in 1952 from the old St. Mary’s Academy. His father, John Henry Thomas Briscoe, was a former St. Mary’s state’s attorney. The younger Briscoe was a 1956 graduate of what was then Mount St. Mary’s College in Emmitsburg, Md., and received a bachelor of law degree from the University of Baltimore in 1960.

Judge Briscoe served as president of the Historic Sotterley Plantation Foundation, the Historic St. Mary’s City Commission and the St. Mary’s County Historical Society.

He sat on the board of directors of the Maryland Center for Civic Education and was on the advisory board of the Chesapeake Bay Field Lab. His memberships included the Rotary Club of Lexington Park.

His first marriage, to Sylvia Weiss, ended in divorce. Survivors include his wife of 29 years, Bonnie Sue Brandt Briscoe of Hollywood; four children from his first marriage, Janice Baldwin, John H. Briscoe Jr. and Dana Briscoe, all of Hollywood, Md., and Lisa Jane Briscoe of Timonium, Md.; a son from his second marriage, Adam Briscoe of Providence Village, Tex.; a sister; nine grandchildren; and a great-granddaughter.