1. On April 4, 1968, civil rights leader Martin Luther King Jr. was assassinated in Memphis, Tennessee. His death sparked outrage and protests across the country and around the world, and is widely recognized as a turning point in the Civil Rights Movement.

2. In 1864, during the American Civil War, the Battle of Saltville took place in Saltville, Virginia, just across the Tennessee border. Union forces led by General Stephen G. Burbridge attempted to seize control of the area's saltworks and other resources, but were ultimately defeated by Confederate forces.

3. On April 4, 1939, the Tennessee Valley Authority (TVA) began operating its first hydroelectric dam, located on the Tennessee River near Muscle Shoals, Alabama. The TVA was created in 1933 as part of President Franklin D. Roosevelt's New Deal, and played a major role in developing infrastructure and improving quality of life in the region.

4. The Great Smoky Mountains National Park, which straddles the Tennessee-North Carolina border, was officially dedicated on April 4, 1940. The park is known for its scenic beauty, abundant wildlife, and historic structures, and attracts millions of visitors each year.

5. On April 4, 1896, the Tennessee legislature passed the infamous "Separate Car Law," which mandated segregated railway cars for black and white passengers. The law was ultimately struck down by the US Supreme Court in 1900 as unconstitutional, but was one of many legal barriers to equality faced by African Americans in Tennessee and throughout the South.