Route 66’s history is one that’s primarily connected with the Nat King Cole song about getting your kicks, and the fun, quirky shops and storefronts along the 2,500 mile road that covers eight states.

But that route was often an uncomfortable—sometimes risky—one for African-American travelers.

One small way to quell that risk was what was called "The Negro Motorist Green Book." It let African Americans on the road know which restaurants they could eat in and which hotels they could stay in starting in the 1930s. 

Historian and scholar Candacy Taylor has been researching the book’s history for her Green Book Project, in which she documents the properties in the Green Book.