[1] At a time when Vermont was overwhelmingly Republican, Leddy lost to Robert Stafford by only 719 votes (50.3% to 49.7%).

[1] Leddy's strong showing in the governor's race, coupled with the win of Democrat William H. Meyer in the election for Vermont's at-large seat in the United States House of Representatives, was an indicator that the state's Democrats were growing in strength after more than 100 years of Republican dominance in statewide elections.

He was confirmed by the United States Senate on August 25, 1966, and received his commission the same day.

[8] His service was terminated on January 9, 1972,[8] due to his death following a heart attack at his Burlington home.

[11] They were the parents of sons John T. and the Reverend James P., and three daughters, Ann, Johannah, and Mary.