In 1936 a Harlem postal worker and activist named Victor H. Green decided to develop a guide that would help African Americans travel throughout the country in a safe and comfortable manner. For three decades, "The Negro Motorist Green Book" (also called "The Negro Travelers' Green Book"), often simply known as "The Green Book," identified places that welcomed black people during an era when Jim Crow laws and de facto segregation made it difficult for them to travel domestically without fear of racial backlash.

Like users of today's popular recommendation sites such as TripAdvisor, travelers collected information during their journeys, which they shared with Green and his team of editors. The data was then incorporated into future editions.

"The Green Book" has recently been rediscovered in popular culture. Atlanta playwright Calvin Alexander Ramsey wrote a play entitled The Green Book, in which a Black military officer and his wife stay in a "tourist home" (private homes identified as safe places for travel) with a Holocaust survivor on the eve of a speech being given by W.E.B. Du Bois in Jefferson City, Mo. Ramsey also published a children's book, "Ruth and the Green Book," illustrated by legendary artist Floyd Cooper that follows a young girl's journey with her family in an expensive car from Chicago to Alabama.

Some of the locations mentioned in the books are still standing today. But not surprisingly, many, if not most, of the businesses that The Root contacted or attempted to locate on foot or by car in Washington, D.C., and Baltimore no longer exist.

Some of the names of the places, like the Casbah restaurant found in the 1956 guide for Washington, D.C., still exist. But this Casbah Café has a different address and has been in existence only for about eight years, so we know it isn't the Casbah of "The Green Book."

Republic Gardens made the cut, listed as a nightclub in the 1956 edition. Most college-educated blacks who have spent any time in D.C. -- certainly in the last 25 years -- are familiar with the hot spot. The venue opened its doors in 1920 on the historic U Street corridor. On the other hand, the Excelsior Club, located in Charlotte, N.C., and the oldest supper club founded by blacks in the Southeast, was not listed in the 1949 or 1956 versions of the guide.

Read it at The Root.