The Negro Motorist Green Book, or Green Books as they were often referred to as, was used by Black families when the needed to travel through segregated America. The Green Book was created by Victor Green, each book had a state by state list of accommodations that would house everyone. My grandmother says she remembers using Green Books as a young child when her family travels. In my copy some states, like Texas, are not even listed in the index.
I noticed that some of the states not listed just so happened to be the same states that Blacks migrated from during the Great Migration (1917-70). On the map I painted those states a dark navy, the mid range blue states are the more neutral states, and the brightest colored states are were Black families migrated to.