Rutgers University Libraries comprises over twenty libraries and centers in New Brunswick, Camden, and Newark, but the most substantial collection for history is located in the Alexander Library on the College Avenue Campus. Here's a page with maps directing you to the all the Rutgers libraries.
Note: The New York area is home to many first-rate collections!
*Rutgers faculty, students, and staff may visit these collections without charge and have quicker than usual access when borrowing their materials via Rutgers interlibrary loan.