President Franklin D. Roosevelt lowered the military draft age to 18 during World War II, sparking the slogan ''old enough to fight, old enough to vote'' among those horrified that Americans could die for their country before participating in its democracy. The movement gained widespread support during the Vietnam War when all male 18- to 20-year-old citizens could be drafted to fight but couldn''t vote on the war''s prosecution. Barry McGuire''s 1965 song ''Eve of Destruction'' captured the anger: ''You''re old enough to kill but not for votin''.'' On July 5, 1971, President Richard Nixon signed the 26th Amendment into law, lowering the voting age from 21 to 18. The amendment was ratified in just 100 days, the fastest approval of any constitutional amendment. In the 1972 elections, 55 percent of 18- to 29-year-old voters turned out, the highest rate for that age group in American history.