“Art as Activism: Graphic Art From the Merrill C. Berman Collection” at the New-York Historical Society is a new exhibit composed 100% from the collection of Rye resident Merrill Berman.
According to the New York Times: "The show offers a fantastic selection of 71 posters from the 1930s to the ’70s. Drawn from the singular collection of Merrill C. Berman, an investor from Rye, N.Y., they show the role visual art has played in political and protest movements in the United States."
(Read the Times article.)
You can also look at some of the work on Berman's own web site (a fantastic collection) and the exhibit pages on the New-York Historical Society web site.