1. On September 23, 1789, President George Washington signed the Judiciary Act of 1789, which established the federal court system and the office of the Attorney General. This act laid the foundation for the modern U.S. legal system.

2. In 1846, the Smithsonian Institution was formally established by an act of Congress, and its first building was completed on the National Mall in 1855. Today, the Smithsonian consists of 19 museums, galleries, and research centers, making it the world's largest museum complex.

3. September 23, 1957, marked the desegregation of the Washington, D.C., public school system. Nine African American students were accompanied by federal troops as they entered previously all-white schools in the city's southeast area, ending decades of racially segregated schools.

4. On September 23, 1976, the Metro transit system opened in Washington, D.C., providing residents and visitors with a fast and efficient way to travel to and from the city's suburbs. Today, Metro operates over 100 miles of track, serving over 600,000 passengers each day.

5. In 1996, the United States Holocaust Memorial Museum opened in Washington, D.C. The museum is dedicated to educating visitors about the history and significance of the Holocaust, and serves as a memorial to the millions of people who lost their lives during this dark period in human history.