The Ulster Historical Society was founded in 1859, largely though the efforts of State Senator George W. Pratt. Pratt, Commanding Colonel of the 20th Regiment, New York State Militia (80th NYSV) was mortally wounded in 1862 at the Second Battle of Bull Run. With his death, the Society became dormant until 1930, when an enthusiastic group let by Judge G.V.D. Hasbrouck revived it.

The Bevier House Museum maintains a library where family histories, church and cemetery records, financial and legal papers, land records, letter and diaries, Ulster County histories and maps, and Revolutionary and Civil War histories can be found.