When was the law, barring US Presidents from contesting the third time, passed?

Franklin D. Roosevelt (1882-1945), a distant cousin of Theodore Roosevelt, was elected President four times, in 1932, 1936, 1940 and 1944.

He spent a longer time in the White House than any other President. In 1951, a constitutional amendment barred presidential candidates from being elected to more than two four years terms.