1. On October 20, 1864, the Battle of Little Blue River took place in Jackson County, Missouri, just across the border from Kansas. Union forces, including the Kansas 2nd and 11th cavalry regiments, engaged Confederate troops in a skirmish that ended inconclusively.

2. In 1890, the University of Kansas football team played its first game on October 20, against Baker University. KU won the game by a score of 22-9, and went on to finish the season with a record of 2-2-1.

3. October 20, 1915, marked the opening of the Panama-California Exposition in San Diego, California. The Kansas City Star newspaper sent a special train of reporters and photographers to cover the event, which celebrated the completion of the Panama Canal and showcased the culture and industry of the American Southwest.

4. On October 20, 1944, the battleship USS Kansas participated in the Battle of Leyte Gulf, a major naval engagement of World War II in the Pacific. The Kansas provided support for the invasion of the Philippines, and helped to neutralize Japanese naval forces that threatened the American landing.

5. In 1968, the musical Hair opened on Broadway on October 20. The rock musical, which included themes of counterculture, sexuality, and pacifism, was controversial and groundbreaking for its time. A touring production of Hair would later come to Lawrence, Kansas, in 1970, drawing protests from local conservative groups.