James W. Loewen is the leading expert on this subject: here is his resource page on sundown towns, including this interactive map, tips on how to discover if your city/town was a sundown town, and much more. See his book Sundown Towns: A Hidden Dimension Of American Racism. You can read the first chapter here.

Note: the following resources focus on sundown towns, as well as how Black Americans navigated them: thus the section includes resources on Black travel guides, such as the Green Book.

Evan Andrews: The Green Book: The Black Travelers’ Guide to Jim Crow America: For nearly 30 years, a guide called the “Negro Motorist Green Book” provided African Americans with advice on safe places to eat and sleep when they traveled through the Jim Crow-era United States.

DeNeen L. Brown: ‘Life or death for black travelers’: How fear led to ‘The Negro Motorist Green-Book’

Hannah Buehler: Sundowners signs taken down in North Tonawanda (in August of 2019.)

Logan Jaffe and ProPublica Illinois: Life in One of the Whitest Towns in America: Anna, Illinois, has a long history of excluding black people. Where does that leave it today?

New York Public Library: Green Book collection. (Primary source.)

New York Public Library: Hackley & Harrison’s hotel and apartment guide for colored travelers. (Primary source.)

Heather A. O’Connel: Historical Shadows: The Links between Sundown Towns and Contemporary Black–White Inequality.

Candacy Taylor: The Roots of Route 66: America’s favorite highway usually evokes kitschy nostalgia. But for black Americans, the Mother Road’s lonely expanses were rife with danger.

Candacy Taylor: Overground Railroad: The Green Book and the Roots of Black Travel in America. (Book).

Teaching Tolerance: Does My Town Have a Racist Past? How students can convert the shameful history of sundown towns in America into a rich opportunity for setting the record straight.