"It is with a heavy heart and a deep sense of grief that we share the passing of our brother, husband, father, and grandfather who died peacefully in Nashville surrounded by his family," reads the statement from his family.

Thompson was also a GOP presidential candidate in 2008, as well as a Watergate attorney. He played D.A. Arthur Branch on "Law & Order" for five years, and also appeared on the show's spinoffs "Special Victims Unit" and "Trial by Jury" as the character.

Thompson, who was born in Sheffield, Ala., shifted between politics and acting frequently throughout his life, but he gained a degree of visibility in 1973, when he served as minority counsel to the Senate Watergate Committee, after having managed the reelection campaign of Sen. Howard Baker (R-Tenn.), the top Republican on the committee.

At one hearing, he asked former White House aide Alexander Butterfield, "Mr. Butterfield, are you aware of the installation of any listening devices in the Oval Office of the president?" Butterfield's confirmation of a secret recording system was a key turning point in the scandal that eventually led to President Richard M. Nixon's resignation.