The RIHS holds the largest and most important historical collections relating to Rhode Island. These collections include 25,000 museum objects, more than 100,000 printed books, 110,000 photographs, 3,400 sound recordings (including oral histories and music), 9 million feet of moving picture film, over 1,100 manuscript collections (measuring over 7,000 linear feet), 3,400 maps, 20,000 prints, 16,000 pieces of ephemera, 15,000 architectural drawings, and several smaller, miscellaneous categories of historical holdings. These collections grow every year, due to gifts and purchases.
The RIHS owns and maintains the John Brown House Museum (52 Power Street, Providence), a National Historic Landmark built in 1788; the Aldrich House (110 Benevolent Street, Providence), also a National Historic Landmark, built in 1822; and the Library (121 Hope Street, Providence). The organization also maintains the Museum of Work and Culture (42 South Main Street, Woonsocket), a regional history museum devoted to the history of northern Rhode Island.