1. On April 20, 1939, the Tennessee Valley Authority was authorized to develop and manage the Tennessee River. This project created hydroelectric power that helped modernize the state and improve economic conditions throughout the region.

2. In 1861, Tennessee seceded from the United States and joined the Confederacy. On April 20 of that year, Governor Isham Harris issued a proclamation calling for the state's citizens to join the southern cause and volunteer to fight for the Confederacy. This proclamation played a crucial role in the state's decision to secede.

3. On April 20, 1814, General Andrew Jackson led American forces to victory against the Creek Indians in the Battle of Emuckfaw. This battle was a major turning point in the Creek War, and helped solidify Jackson's position as a military leader.

4. In 2010, the Deepwater Horizon oil spill occurred in the Gulf of Mexico. Although the spill did not take place specifically in Tennessee, it had a significant impact on the state's environment and economy. On April 20 of that year, Governor Phil Bredesen declared a state of emergency in response to the spill and its potential impact on the state.

5. On April 20, 2018, Waffle House shooting occurred in Antioch, Tennessee. A gunman entered the restaurant and opened fire, killing four people and injuring several others. The shooter was later apprehended by authorities and charged with murder. The incident sparked a nationwide discussion about gun violence and the need for stricter gun control laws.