1. On December 20, 1860, the state of Alabama officially seceded from the United States, becoming the fourth state to do so.

2. In 1820, the state capital of Alabama was moved from Cahaba to Tuscaloosa on December 20th.

3. On December 20, 1956, Rosa Parks was arrested for refusing to give up her seat on a Montgomery bus, sparking the Montgomery Bus Boycott and the Civil Rights Movement.

4. The Battle of Nashville, a major battle of the American Civil War, began on December 20, 1864, with Confederate forces under General John Bell Hood facing off against Union forces under General George H. Thomas.

5. On December 20, 1983, Alabama-native astronaut William R. Pogue returned to Earth after a 84-day mission aboard the Skylab space station. Pogue, a native of Okmulgee, Alabama, had previously served as a astronaut on the Apollo 19 and Apollo 20 missions.