This Day In History for July 1

1867, Canada became a self-governing dominion of Great Britain as the British North America Act took effect.

On this date:
In 1863, the Civil War Battle of Gettysburg began.

In 1898, during the Spanish-American War, Theodore Roosevelt and his "Rough Riders" waged a victorious assault on San Juan Hill in Cuba.
In 1943, "pay-as-you-go" income tax withholding began.

In 1946, the United States exploded a 20-kiloton atomic bomb near Bikini Atoll in the Pacific.

In 1961, Diana, the princess of Wales, was born near Sandringham, England. (She died in August 1997 in a car crash in Paris at age 36.)

In 1963, the US Post Office inaugurated its five-digit ZIP codes.

In 1968, the United States, Britain, the Soviet Union and 58 other nations signed the Nuclear Nonproliferation Treaty.

In 1969, Britain's Prince Charles was invested as the Prince of Wales.

In 1980, "O Canada" was proclaimed the national anthem of Canada.

In 1997, Hong Kong reverted to Chinese rule after 156 years as a British colony.