Here is an excellent photographic summary of the history of the African American Community in Princeton, NJ, presented by the Pride Unity Leadership Sisterhood Esteem (PULSE) or Princeton High School. 

This history starts with Princeton as it was in the 1920s and 1930s:

“Because Princeton was a Jim Crow town, the colored population was not able to shop in certain stores, eat at restaurants or attend many social establishments so there were many colored businesses and establishments in the area from Nassau Street to Birch Avenue…”