On January 14th:

 1784  The United States Ratifies the Treaty of Paris, Officially Ending the Revolutionary War

On January 14th, 1784, the United States ratified the Treaty of Paris, officially bringing an end to the Revolutionary War and recognizing its independence from Great Britain.

 1943  Franklin D. Roosevelt Becomes the First U.S. President to Travel by Airplane on Official Business

A pioneering moment in presidential history occurred on January 14th, 1943, when Franklin D. Roosevelt became the first U.S. president to travel by airplane on official business. This marked a new era in presidential transportation.

1969  An Explosion on the USS Enterprise Kills 27 Crew Members

A tragic event occurred on January 14th, 1969, when an explosion on the aircraft carrier USS Enterprise resulted in the loss of 27 crew members. The incident prompted improvements in safety measures.