The US Postal Service was founded.
Benjamin Franklin was named the first Postmaster General.
Source
The Summer Olympic Games opening ceremony was held outdoors for the first time ever.
President Harry Truman signed the National Security Act.
Francisco Pizarro became the Governor of Castile, which is a historic area of modern-day Peru.
In one day, Facebook lost $120 billion in value on the stock market.
As part of the War of the Roses in England, the Battle of Edgcote took place.
