April 17, 1951 Mickey Mantle, 19, plays his first big-league game for the New York Yankees.
April 18, 1906 A massive earthquake and the resulting fire devastate San Francisco.
April 19, 1775 The "shot heard 'round the world" in Massachusetts starts the Revolutionary War.
April 20, 1999 Two students at Columbine High School in Colorado go on a shooting rampage, killing 12 fellow students, a teacher, and themselves.
April 21, 1977 The musical Annie opens on Broadway.