In 2019, the Best Picture Oscar went to Green Book, a movie based very loosely on The Negro Motorist Green Book, an annual Jim Crow-era travel guide; known colloquially as “The Green Book.”

It listed hotels, restaurants, and gas stations that were safe for Black travelers to frequent; such oases of safety were sometimes hundreds of miles apart.

Overground Railroad is the first book to consider the guide’s historical role, and its lasting impact on African American travel today.