Dennehy was born on July 9, 1938, in Bridgeport, Conn., and grew up in Brooklyn and on Long Island. A history major, he enrolled at Columbia on a football scholarship, though, he said later, what he really wanted to do was perform with the Columbia Players. “In those days, the Players had an artistic definition of themselves which didn’t allow a football player to be active,” he told CCT in 1999.
Dennehy’s first newspaper notices were not as an actor, but as a Lion. An All-Ivy League honoree, the 6-foot-3-inch offensive lineman was picked to be one of the senior captains, but in July 1959 The New York Times ran an article headlined “Football Captain-Elect Drops Out of Columbia.” Dennehy, who said he had struggled academically, left school to join the Marines, serving in the United States, South Korea and Japan. He completed his B.A. in 1965.
As for his acting career, Dennehy said, “I was an overnight success — after 15 years.” He performed in community theater productions, mostly on Long Island, and in the mid-1970s branched out to NYC. His first mention as an actor in the Times was in 1976, for a showcase production of Ivanov. An agent who was looking for “a pro football type” for the movie Semi-Tough saw the show. Dennehy was cast, and small roles in movies and TV series followed quickly. He later starred in the films First Blood (1982), Gorky Park (1983), Cocoon (1985), F/X (1986), Presumed Innocent (1990) and Tommy Boy (1995).
In 1990 Dennehy received the first of six Emmy nominations, for the TV movie A Killing in a Small Town. He played John Wayne Gacy in the 1992 mini-series To Catch a Killer, and from 1992 to 1996 played Chicago police investigator Jack Reed in six TV movies, directing and writing four. In recent years Dennehy had recur- ring roles in several TV series, including The Blacklist.
His first love, however, was the stage. Dennehy made his Broadway debut in 1995 in Translations; after winning acclaim for his portrayal of Willy Loman in Death of a Salesman (1999), his roles included Long Day’s Journey Into Night (2003), Love Letters (2014) and The Iceman Cometh (2015) — his second time in the show. He portrayed Hickey in 1990 and Larry in 2015. Dennehy was inducted into the American Theater Hall of Fame in 2010.
The College presented Dennehy with a John Jay Award for distinguished professional achievement in 1986, and he remained a loyal alumnus. He lent his distinct voice to a promotional video for the University and was the College’s Class Day speaker in 2000.
Dennehy’s first marriage, to Judith Scheff, ended in divorce. He is survived by his wife, Jennifer Arnott; children, Elizabeth, Kathleen, Deirdre, Cormac and Sarah; and seven grandchildren.