On March 29, 1951, Julius and Ethel Rosenberg were convicted of passing US atomic secrets to the Soviet Union. The couple was sentenced to death on April 3 under the Espionage Act of 1917, 18 U.S.C 794. They were then executed two years later on June 19, 1953 in New York State's Sing Sing Prison. View the FBI's files on the Rosenbergs.

On March 29, 1867, the British Parliament passed the British North America Act, a constitutional document creating a united Dominion of Canada. It went into effect on July 1 that year.