CHARLES SUMNER, R-MA
Missed more than three years—from May 1856 through December 1859—after being attacked with a cane by Rep. Preston Brooks (D-SC) on the Senate floor.
CARTER GLASS, D-VA
Took a leave of absence due to heart problems in 1942. His seat remained empty until his death in 1946.
LYNDON B. JOHNSON, D-TX
Had a heart attack in 1955 and took five months to recover.
KARL MUNDT, R-SD
Suffered a stroke in 1969 and was largely absent for the rest of his term.
JOE BIDEN, D-DE
Had surgery for two aneurysms in 1988 and was out for seven months.
Photography: (Glass) Library of Congress, Prints and Photographs Division; (Mundt) Bettmann/Corbis/AP Images; (Biden) Nancy Stone/Chicago Tribune