Event:
Belgium, Luxembourg and Netherlands sign Unity treaty
More Notable Events on July 18:
1994 Comet Shoemaker-Levy collides with Jupiter
1994 Crayola announces introduction of scented crayons
1932 U.S. and Canada sign a treaty to develop St. Lawrence Seaway
1927 Ty Cobb's 4,000th career hit
1872 Britain introduces secret ballot voting
