VOX:

In the 1930s, as the spread of automobiles spurred American drivers to take long trips to explore the country, black drivers who took to America’s roads regularly experienced discrimination during their travels.

But in 1936, Victor Hugo Green, a black postal worker, created a guide that would allow African Americans to embrace the adventure and road trips enjoyed by their white counterparts. The result was The Negro Motorist Green Book, the most popular guide for black travelers for three decades.

If you want more, check out “The Green Book: Guide to Freedom” on the Smithsonian channel.