JACKSON, Miss. — Seven-term Republican Sen. Thad Cochran, who used seniority to steer billions of dollars to his home state of Mississippi, has died. He was 81.

Cochran's final chief of staff, Brad White, said Cochran died Thursday.

Cochran was elected to the U.S. House in 1972. When he won a Senate seat in 1978, he became the first Republican since Reconstruction to win statewide office in Mississippi.

He led the Appropriations Committee in 2005-06 and regained the chairmanship in January 2015, when the GOP retook the Senate.

Known for working across party lines, Cochran easily won most of his re-election campaigns. However, he struggled before winning a 2014 Republican primary over a tea party-backed state lawmaker who received financial support from libertarian-leaning groups that criticized Cochran as a big spender.