Senator Robert Byrd of West Virginia, the longest-serving senator in American history, died Monday at the age of 92, a spokesman for the family said.
Byrd, a Democrat who served in the U.S. Senate since 1959, had been plagued by health problems in recent years and was confined to a wheelchair. He had skipped several votes in Congress in the past months.
Jesse Jacobs, a family spokesman, said Byrd died peacefully at about 3 a.m. at Inova Hospital in Fairfax, Va.
He was the oldest member of the 111th Congress.
The passing of Sen. Byrd will not affect the balance of power in the Senate. West Virginia Governor Joe Manchin, a Democrat, will appoint a replacement senator to serve out the remainder of Byrd's term, which ends in 2012.
Byrd threw his support behind Barack Obama a week after the then-senator lost the West Virginia Democratic primary to Hillary Clinton during the 2008 presidential campaign -- an endorsement that symbolized the shift in his views on race.
Once a member of the Klu Klux Klan, it was the defining moment in his lifelong effort to convince the American public of his changed views on race.
"I have done my best to do the right thing," Byrd said during a March 2005 interview with Fox News, during which he was questioned about his KKK membership in the early 1940s.