The Christiana Incident offers a snapshot of the U.S. when the country was sorting into states where slavery was upheld and states that had abolished it, and what racist tension looked like at border states in the mid-1850s.
Research:

Behind the Scenes Minis: Carry-on Bags
28:38

Gustave Flaubert and the ‘Madame Bovary’ Trial
45:15

Elizabeth Bisland, Beyond the Trip Around the World
42:54