Panama Canal By DANNY N. Nov 3, 1903 Panama Gains Independence Panama gains independence from Colombia Period: Jan 20, 1904 to Aug 20, 1914 Construction of Canal Aug 15, 1914 Canal Opens Official opening of canal Period: Jan 1, 1960 to Dec 31, 1969 1960's anti American riots Sep 7, 1977 Treaties Signed -Panama Canal becomes International waterway. -United States give 60% of Canal Zone back to Panama. Dec 31, 1999 Canal Zone fully Returned Panama canal and canal zone returned to Panama.