James Oliver Eastland of Mississippi, 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. He was not a candidate in the special election to fill that vacancy, but the following year, he successfully challenged the incumbent for the seat. In 1956 Eastland became chairman of the Judiciary Committee, a post he held for more than 22 years—one of the longest service records of any Senate committee chair. As president pro tempore from 1972 to 1978, Eastland served as acting vice president for short periods in 1973 and 1974, when the vice presidency was vacant. A segregationist and opponent of civil rights legislation, Eastland signed the Southern Manifesto in 1956, a statement that called for resistance to desegregation in public schools in the wake of the Supreme Court’s landmark Brown v. Board of Education of Topeka decisions. 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 Eastland took a position, he "proved almost impossible” to move. “Indeed it requires nearly the entire Senate to budge him." In 1964 Mansfield carefully maneuvered the Civil Rights Act around Eastland’s committee to bring it to passage. Eastland retired from the Senate in 1978.