Professor Greenberg taught at Trinity for most of her career, with a few brief stints elsewhere (University of Helsinki, Finland; Columbia University; Harvard University; Nankai University, China). She taught courses in African American history and the history of race in the U.S., as well as courses on many social and cultural history topics including crime, protest movements, Star Trek, and American society during and after the Cold War. Professor Greenberg's research interests have been equally varied, ranging from African American communities during the Great Depression to grass-roots organizing in the Civil Rights movement, and from postwar liberalism to Black-Jewish relations. Her most recent book, a history and community memoir of civil rights organizing in Marks, Mississippi, co-authored with a COFO activist who worked there, was published in January of 2023. Her current projects include a history of civil rights organizations' views about "hate speech" legislation, and work on race and mass incarceration.