His tenure is probably best known for his categorical opposition to the death penalty and for signing into law the bill establishing the University of Massachusetts Boston.

Born in Lawrence, Massachusetts to a family with deep colonial roots, Peabody played college football at Harvard University, where he earned honors as an All-American lineman.

He served in the United States Navy in World War II before embarking on a political career noted more for its failures than its successes.

[7] He was awarded the Knute Rockne Memorial Trophy for best collegiate lineman in 1941,[4] and was inducted into the College Football Hall of Fame in 1973.

[7] Peabody served in the United States Navy during World War II, primarily as a Lieutenant aboard the USS Tirante in the Pacific Ocean theater.

In 1958, Peabody ran for Attorney General of Massachusetts, but lost in the Democratic primary to Edward McCormack, Jr. by nine percentage points.

In the 1962 gubernatorial election, Peabody was victorious in the race for governor, upsetting the Republican incumbent John A. Volpe by only 4,431 votes out of over two million cast.

[17] On April 1, 1964, the governor's 72-year-old mother, Mary Parkman Peabody, made headlines when she was arrested at the Ponce de Leon Motor Lodge in St. Augustine, Florida, for attempting to be served in an integrated group at a racially segregated restaurant.

Peabody's loss was variously attributed to his controversial opposition to the death penalty, his stiff demeanor in television appearances, and a bruising defeat he suffered early in his term in opposing the winning candidate for Speaker of the Massachusetts General Court.

In 1983, he moved to Hollis, New Hampshire, where he ran unsuccessfully for local and statewide political office several times, including for the U.S. Senate in 1986 against the Republican incumbent, Warren Rudman.

However, the primary is non-binding, and, at the prerogative of the presidential nominee, Bill Clinton of Arkansas, the vice-presidential nomination eventually went to Al Gore of Tennessee.