Stop in to the History Center through July 24 to view a collection of Clam Festival posters in the Stonewall Gallery. See how poster styles have changed over the years, from the vivid fluorescent colors of the 1960s and ’70s to the painterly streetscapes of the 2010s. Also on view in the Gallery are Clam Festival artifacts and objects ranging from printed maps and brochures to postcards and trophies. The Stonewall Gallery is open Tuesday through Saturday from 10:00-5:00.