RUSSELL LONG - (D) of Louisiana - Dec. 31, 1948 to Jan. 3, 1987 - 38 years, 3 days: The son of a powerful Louisiana political family, Senator Long took over his father and mother’s Senate seat and helped President Lyndon Johnson push many of his “Great Society” social reforms through the Senate in the 1960s. Long is seen here in Washington, DC, in this undated file photo. Newscom/FILE
RICHARD RUSSELL - (D) of Georgia - Jan. 3, 1933 to Jan. 21, 1971 - 38 years, 18 days: Senator Russell was an early defender of the New Deal and a chairman of the Senate Armed Services and Appropriations Committees. One of the Senate office buildings in Washington is named in his honor. Russell (r.) is seen here in 1963 with a young Max Cleland (D) of Georgia, who went on to take Russell's seat in the Senate. Newscom/FILE
ERNEST HOLLINGS - (D) of South Carolina - Nov. 9, 1966 to Jan. 3, 2005 - 38 years, 1 month, 25 days: Senator “Fritz” Hollings focused on poverty and hunger as a senator, advocating for a national food-stamp program after doing fact-finding tours of some of his state’s most desperate areas. He was an unsuccessful presidential candidate in 1984. Seen here, Hollings discusses the collapse of Enron during hearings held in December 2001. Andy Nelson/The Christian Science Monitor/FILE
TED STEVENS - (R) of Alaska - Dec. 24, 1968 to Jan. 3, 2009 - 40 years, 10 days: A former Senate majority leader and later a chairman of the Senate Appropriations Committee, Senator Stevens directed billions of federal dollars back home. He was the longest-serving Republican in the history of the Senate and served in the federal government since before Alaska was a state. Stevens is seen here after making his last formal speech on the Senate floor on Nov. 20, 2008 on Capitol Hill. Lauren Victoria Burke/AP/FILE
JOHN STENNIS - (D) of Mississippi - Nov. 5, 1947 to Jan. 3, 1989 - 41 years, 1 month, 29 days: Chairman of the Senate Armed Services Committee for a dozen years, Senator Stennis is credited with helping to build the modern US Navy. One of the Navy’s nuclear aircraft carriers is named in his honor. Stennis Center for Public Service Leadership
CARL HAYDEN - (D) of Arizona - Mar. 4, 1927 to Jan. 3, 1969 - 41 years, 9 months, 30 days: “The silent senator” was the longest-serving member of Congress (he also spent 15 years in the House) until Byrd broke his record in 2009. Senator Hayden eschewed lengthy speeches on the Senate floor, preferring instead to negotiate one-on-one with colleagues to achieve policy goals like natural-resource development. US Senate Historical Office
EDWARD KENNEDY - (D) of Massachusetts - Nov. 7, 1962 to Aug. 25, 2009 - 46 years, 9 months, 18 days: Known as the “Lion of the Senate,” Senator Kennedy began his career as the “other” Kennedy – overshadowed by brothers John and Robert – but ended it as a deeply respected legislator on both sides of the aisle. Health-care reform was his signature issue; he saw it pass the Senate, but died before it became law. Kennedy is seen here in 2004 delivering a speech about the effect of the war in Iraq at George Washington University in Washington. Manuel Balce Ceneta/AP/File
STROM THURMOND: (D, then R) of South Carolina - Dec. 24, 1954 to April 4, 1956; Nov. 7, 1956 to Jan. 3, 2003 - 47 years, 5 months, 8 days: An unsuccessful candidate for president under the banner of the States’ Rights Party in 1948, Senator Thurmond’s career was defined by his opposition to civil rights legislation in the 1950s and ‘60s. He filibustered a civil rights bill for more than 24 hours in 1957. Thurmond is seen here listening to Attorney General John Ashcroft testify before the Senate Judiciary Committee in Washington in December 2001. Andy Nelson/The Christian Science Monitor/File
DANIEL INOUYE - (D) of Hawaii - Jan. 3, 1963 to present - 47 years, 5 months, 25 days: Senator Inouye replaced Byrd as chair of the Senate Appropriations Committee in 2009. The decorated World War II veteran has emphasized military issues in the Senate, serving as the inaugural chairman of the chamber’s Intelligence Committee in 1976. Here, Inouye speaks with Defense Secretary Robert Gates on Capitol Hill on June 16 before the start of the committee's hearing on the Defense Department's 2011 fiscal year budget. Pablo Martinez Monsivais/AP
ROBERT BYRD - (D) of West Virginia - Jan. 3, 1959 to June 28, 2010 - 51 years, 5 months, 25 days: Twice the Senate majority leader and a long-time chairman of the Senate Appropriations Committee, Senator Byrd used his seniority to stick up for his home state, sending billions of federal dollars to West Virginia during his tenure. Byrd is seen here in April 2005 speaking in Washington. Kevin Lamarque/Reuters
Longtime Democratic U.S. Rep. Edward Markey has won the U.S. Senate seat long held by John Kerry, now US Secretary of State. Markey defeated Republican political newcomer and former Navy SEAL Gabriel Gomez.
ByBob Salsberg and Steve LeBlanc, Associated Press
John Ferrarone / Worcester Telegram & Gazette / AP
Longtime Democratic U.S. Rep. Edward Markey defeated Republican political newcomer Gabriel Gomez in a special election on Tuesday for the state's U.S. Senate seat long held by John Kerry, a race that failed to draw the attention that the state's 2010 special Senate election did.