1. In 1825, the first boat to navigate the Wabash Canal arrived in Washington, D.C. This canal, which connected the Wabash River with Lake Erie, played a crucial role in the transportation of goods in the mid-19th century.

2. In 1864, Union General William T. Sherman telegraphed President Abraham Lincoln a message from his headquarters in Atlanta, Georgia. The message famously read, "I beg to present you as a Christmas gift the city of Savannah."

3. In 1917, President Woodrow Wilson arrived in Washington, D.C. after a trip to France to meet with Allied leaders. While in France, Wilson had proposed his plan for a League of Nations, which he hoped would help prevent future wars.

4. In 1963, President Lyndon B. Johnson signed the "Clean Air Act" into law. This legislation established a national program to control air pollution, and has been amended several times over the years to strengthen its provisions.

5. In 2014, the Smithsonian Institution's National Museum of American History opened a major new exhibition called "The Price of Freedom: Americans at War." The exhibit features artifacts and exhibits from various wars in U.S. history, and explores the impact of war on American society and culture.