The Curse of Tippecanoe (or the Zero Year Curse).

The Curse of Tippecanoe (also known as Tecumseh's Curse, the 20-year Curse or the Zero Year Curse) is a coincidence or urban legend surrounding the deaths in office of presidents of the United States who were elected in years ending in zero and divisible by 20. According to the legend, Tenskwatawa, leader of Native American tribes defeated in 1811 at the Battle of Tippecanoe by a military expedition led by William Henry Harrison, had cursed the "Great White Fathers".

Since 1840, eight presidents have died in office. Seven of them were elected in years divisible by 20: William Henry Harrison (1840), Abraham Lincoln (1860), James A. Garfield (1880), William McKinley (1900), Warren G. Harding (1920), Franklin D. Roosevelt (1940) and John F. Kennedy (1960). Two former presidents elected in applicable years, Ronald Reagan in 1980 and George W. Bush in 2000, did not die in office.

1840, William Henry Harrison, April 4, 1841. Cause: Pneumonia.
1860, Abraham Lincoln, April 15, 1865. Cause: Assassinated.
1880, James A. Garfield, September 19, 1881. Cause: Assassinated
1900, William McKinley, September 14, 1901. Cause: Assassinated
1920, Warren G. Harding, August 2, 1923. Cause: Heart attack
1940, Franklin D. Roosevelt, April 12, 1945. Cause: Cerebral hemorrhage
1960, John F. Kennedy, November 22, 1963. Cause: Assassinated
1980, Ronald Reagan (did not die in office).