1. On August 14, 1971, the Washington Metropolitan Area Transit Authority (WMATA) officially began operations. Consisting of a network of buses and trains connecting the District of Columbia, Maryland, and Virginia, the WMATA has become an integral part of daily life for many residents and visitors.

2. August 14, 1935, marked the opening of the National Archives Building in Washington, D.C. Home to some of the most significant documents in American history, including the Constitution, the Declaration of Independence, and the Bill of Rights, the building has become a popular destination for tourists, researchers, and history buffs.

3. On August 14, 1791, President George Washington signed into law the first patent ever issued in the United States. The patent was granted to Samuel Hopkins for a method of making potash, a substance used in soap and glassmaking.

4. August 14, 1996, saw the grand opening of the International Spy Museum in Washington, D.C. Featuring exhibits on espionage techniques, tools, and stories from around the world, the museum has become one of the city's most popular attractions.

5. Finally, on August 14, 1937, the National Gallery of Art opened its doors to the public. Home to some of the world's most famous works of art, including paintings by da Vinci, Rembrandt, and Van Gogh, the Gallery has become a symbol of D.C.'s cultural and artistic richness.

Overall, August 14 has been a significant day in the history of the District of Columbia, with important milestones in transportation, arts, culture, and innovation.