A lifelong Vermonter, Jeffords first ran for Congress in 1974 after a failed bid for governor, and then ran for Senate in 1988 when Sen. Bob Stafford retired.
Jeffords chafed against his party, often acting as a crucial swing vote siding by Democrats, while remaining popular with his constituents. In 2001, Jeffords left the Republican Party and became an Independent. He retired in 2007.
"I join Vermonters and citizens nationwide today in celebrating the life of Jim Jeffords, a true gentleman and an independent-minded maverick in the best tradition of our state," said Vermont Gov. Peter Shumlin. "He followed his sense of right in all that he did, and was never afraid to seek compromise by reaching across the aisle for the good of our country."
Diane Derby, his former communications director, confirmed Jeffords' passing at Knollwood, a military retirement community in Washington, D.C., where he lived his last eight years. He is survived by his two children and two grandchildren.
"During his more than 30 years in Washington, Jim never lost the fiercely independent spirit that made Vermonters, and people across America, trust and respect him," President Obama said in a statement. "Whatever the issue -- whether it was protecting the environment, supporting Americans with disabilities, or whether to authorize the war in Iraq -- Jim voted his principles, even if it sometimes meant taking a lonely or unpopular stance. Vermonters sent him to Washington to follow his conscience, and he did them proud."