1. In 1807, former Vice President of the United States Aaron Burr was arrested in the District of Columbia and charged with treason for allegedly plotting to establish an independent nation in the southwestern United States. After a sensational trial, Burr was acquitted.

2. On January 19, 1861, just six weeks before the start of the Civil War, the Maryland General Assembly voted narrowly to remain in the Union. The decision was a blow to the Confederate cause, as Maryland's strategic location between the North and South made it a crucial border state.

3. In 1915, the National Advisory Committee for Aeronautics (NACA) was established in Washington, D.C. NACA was a precursor to NASA and was responsible for conducting research and development in the field of aviation.

4. On January 19, 1961, President-elect John F. Kennedy arrived in Washington, D.C. to begin preparations for his inauguration. Kennedy's inauguration the following day would mark the beginning of a new era in American politics and would be remembered for his famous line, "Ask not what your country can do for you, ask what you can do for your country."

5. In 2019, the first Women's March on Washington was held on January19, in response to the Trump Administration's policies and rhetoric regarding women's rights, immigration, and other issues. The march drew hundreds of thousands of participants to the National Mall and other locations around the country.