On May 31, 1926, the Sesquicentennial International Exposition opened in Philadelphia, Pennsylvania. It was planned to mark the 150th anniversary of the signing of the Declaration of Independence and the 50th anniversary of the 1876 Centennial Exposition.
On February 18, 1939, the Golden Gate International Exposition opened in San Francisco, California. Initially planned to honor the completion of the Bay Bridge and the Golden Gate Bridge, it was expanded to honor all the countries and continents surrounding the Pacific.
On April 4, 1925, the US Post Office issued the first three stamps in a multi-year series honoring important events and people from the American Revolution. The stamps were issued for the sesquicentennial (150th) anniversary of the Revolution.
On February 18, 1939, the Golden Gate International Exposition opened in San Francisco, California.