Johnny Carson announces he will retire next year from Tonight Show More Notable Events on April 22: 1994 In Denmark the largest lollipop, weighing 3,011 pounds, made
1992 Holocaust Museum dedicated in Washington D.C.
1970 1st Earth Day held internationally to conserve natural resources
1915 1st military use of chlorine poison gas by Germany in WW I
1898 U.S. President McKinley orders blockade of Cuban harbors