1842 – John Greenough is granted the first patent for the sewing machine.
1848 – Karl Marx and Friedrich Engels publish The Communist Manifesto.
1866 – Lucy Hobbs Taylor becomes the first American woman to graduate from dental school.
1878 – The New Haven, Conn., Telephone Co. published the first phone directory. It listed 50 subscribers.
1855 – The Washington Monument is dedicated.
1953 – Researchers Francis Crick and James Watson discovered the double helix structure of the DNA molecule.
1965 – Black Muslim leader Malcolm X was assassinated at a rally in New York.
1972 – President Richard Nixon visits the People’s Republic of China to normalize Sino-American relations.
1975 – Watergate scandal: Former Attorney General John Mitchell and former White House aides H.R. Haldeman and John Ehrlichman are sentenced to prison.