1. On August 20, 1833, the town of Louisville was incorporated as a city in Kentucky. This marked a significant milestone in the development of the city, which had grown dramatically in the preceding decades due to its strategic location on the Ohio River.

2. The famous Kentucky Derby, one of the most famous horse races in the world, was first run on August 20, 1875. Held annually at Churchill Downs in Louisville, the race has become a cultural institution in Kentucky and a major event on the international racing calendar.

3. On August 20, 1823, the poet and songwriter Stephen Foster was born in Lawrenceville, Pennsylvania. Although he spent most of his life in Pennsylvania and New York, Foster composed several songs that have become closely associated with Kentucky, including "My Old Kentucky Home" and "Old Folks at Home."

4. August 20, 1866, marked the beginning of one of the deadliest race riots in American history, known as the Louisville Riot of 1866. The riot was sparked by tensions between black residents and white dockworkers over competition for jobs, and resulted in at least 48 deaths and widespread destruction of property.

5. On August 20, 1955, a group of African American students attempted to integrate the public schools in Marion County, Kentucky. The students were met with hostile resistance from white residents and were eventually forced to withdraw from the schools. The incident highlighted the ongoing struggle for civil rights in Kentucky and the deep-seated racial divisions that persisted in many parts of the state.