Meet 6 of the Longest-Serving Politicians in U.S. History

Iowa Gov. Terry Branstad at a proclamation signing at Jordan Creek Elementary School, in West Des Moines, Iowa. On Dec. 14, the six-term Republican marks his 7,642nd day of service as governor, making him the longest-serving governor in American history.
Iowa Gov. Terry Branstad at a proclamation signing at Jordan Creek Elementary School, in West Des Moines, Iowa. On Dec. 14, the six-term Republican marks his 7,642nd day of service as governor, making him the longest-serving governor in American history.Charlie Neibergall—AP
By TIME Photo
Iowa Gov. Terry Branstad at a proclamation signing at Jordan Creek Elementary School, in West Des Moines, Iowa. On Dec. 14, the six-term Republican marks his 7,642nd day of service as governor, making him the longest-serving governor in American history.
Iowa Gov. Terry Branstad at a proclamation signing at Jordan Creek Elementary School, in West Des Moines, Iowa. On Dec. 14, the six-term Republican marks his 7,642nd day of service as governor, making him the longest-serving governor in American history. Charlie Neibergall—AP
President Franklin Delano Roosevelt waves from a lectern just after he took his fourth Oath of Office in Washington in 1945. With him are his Vice President Harry S. Truman and his son James Roosevelt. Roosevelt, the longest serving president in American history, was the only president to serve more than two terms.
President Franklin Delano Roosevelt waves from a lectern just after he took his fourth Oath of Office in Washington in 1945. With him are his Vice President Harry S. Truman and his son James Roosevelt. Roosevelt, the longest-serving president in American history, was the only one to serve more than two terms.Photoquest/Getty Images
Speaker of the House Sam Rayburn with his gavel. Rayburn served as the Speaker of the House for 17 years, the longest tenure in U.S. history.
Speaker of the House Sam Rayburn with his gavel. Rayburn served as Speaker for 17 years, the longest tenure in U.S. history. Alfred Eisenstaedt—The LIFE Picture Collection
Rep. John Dingell, D-Mich., in his Rayburn office. Dingell served for more than 59 years—the longest Congressional tenure in U.S. history.
Rep. John Dingell, D-Mich., in his Rayburn office. Dingell served for more than 59 years—the longest Congressional tenure in U.S. history.Tom Williams—CQ-Roll Call/Getty Images
Sen. Robert Byrd, D-W.Va., on Capitol Hill in Washington. Byrd was the longest-serving U.S. Senator at the time of his death.
Sen. Robert Byrd, D-W.Va., on Capitol Hill in Washington. Byrd was the longest-serving U.S. Senator at the time of his death.Carolyn Kaster—AP
A bronze statue of Richmond Mayor Hilmar Moore is displayed outside City Hall in Richmond, Texas. Moore, who was appointed as mayor in 1949 and then won 32 consecutive elections, was the longest serving mayor in the U.S. when he died.
A bronze statue of Richmond Mayor Hilmar Moore, is displayed outside City Hall in Richmond, Texas. Moore, who was appointed as mayor in 1949 and then won 32 consecutive elections, was the longest serving mayor in the U.S. when he died after serving as mayor for 63 years.Bob Levey—The New York Times/Redux

More Must-Reads from TIME

Contact us at letters@time.com