Police checks on drunk drivers was declared constitutional by the US Supreme Court.
'Uncle Sam' became the official nickname of the United States.
Yellowstone National Park closed for the first time in US history due to ongoing fires.
The United States of America founded Space Command (SPACECOM), the first of its kind in the US Armed Forces.
The National Black Independent Political Party (NBIPP) was formed in the US.
America banned all advertisements of cigarettes on TV and radio.
The Zodiac Killer claimed two more victims.
An announcement was made to say that all cigarette packages in the US must display health warnings.
Underground America Day was first observed, which recognizes the approximately 6,000 people who live in some form of underground architecture across North America.
The Arecibo Ionospheric Observatory in Arecibo, Puerto Rico, was officially opened.
The United States Postal Service introduced ZIP codes for US mail.
The US signed the Equal Pay Act to reduce the difference in pay between sexes.
The United States became the first country to legalize a birth control pill.
The District Court ruled that segregation was unconstitutional in Montgomery.
The director of the CIA launched Project MKUltra, the US' top secret mind control program.
Construction of The Pentagon was completed.
The United States Congress formally recognized the Pledge of Allegiance and added it to the Federal Flag Code.
Voice of America, the US' official external radio and television service, began broadcasting.
After 14 years of work, Mount Rushmore was completed.
The first canned beer received instant approval from customers.
USPTO received a trademark for the Kleenex brand name.
US Post Office banned customers from mailing children and animals.
Alcohol became illegal in most states of America.
The first US airmail stamps were issued, costing 24 cents.
The US daylight saving time went into effect.
The Spanish Flu received its first case in the US.
Frugal parents mailed their four-year-old child 73 miles from their home to the child's grandparents.
The United States Department of Labor was formed.
Father's Day was celebrated for the first time in the US.
The first installment of concrete was poured into the Panama Canal.
The Williamsburg suspension bridge opened.
The largest music fraternity in the USA, Phi Mu Alpha Sinfonia, was founded.
Labor Day became an official US holiday.
The Pledge of Allegiance was first recited in American schools.
The Baltimore Afro-American newspaper was published for the first time.
Ellis Island opened as a US immigration inspection station.
The United States Congress established Yosemite National Park.
The US Congress abolished the gold dollar and three-dollar coins.
A national strike began in the United States, calling for an eight-hour workday instead of 12 hours.
The oldest soft drink brand, Dr Pepper, sold its very first bottle in the USA.
American Congress eliminated the twenty-cent coin.
The United States Weather Bureau made its first comprehensive weather forecast.
The United States Department of Justice was formed.
The US adopted the 15th Amendment, guaranteeing citizens the right to vote.
US cavalrymen massacred 200 Piegan Blackfeet in the Marias Massacre.
The University of California was founded.
The US Congress approved the 5 cent nickel.
The United States issued gold certificates to battle counterfeit notes.
The United States Secret Service was formed.
The US Congress passed legislation that allowed the 'In God We Trust' inscription on the currency.
