James Oliver Eastland, widely known as "Big Jim," served in the U.S. Senate for 36 years. In 1941 he was appointed to fill a vacancy caused by the death of Democrat Pat Harrison, having agreed that he would not run in the special election to be held three months later. Eastland subsequently ran successfully in the Democratic primary and general election the following year. In the Senate, Eastland served on the Agriculture and Judiciary Committees. In 1956 he became chairman of the Judiciary Committee, a post he held for more than 22 yearsamong the longest continuous service of any Senate committee chair. He also served as president pro tempore from 1972 to 1978. Staunchly opposed to the passage of civil rights legislation, Eastland often used his powerful position as chairman of the Judiciary Committee to prevent civil rights bills from being considered before the full Senate. Senate Majority Leader Mike Mansfield of Montana observed that, once having taken a position, James Eastland "proved almost impossible” to move. “Indeed it requires nearly the entire Senate to budge him."