Influential members of the Maine Historical Society included many of Maine's Yankee businessmen, intellectuals, philanthropists, and political figures, including James Phinney Baxter, Josiah Crosby, George J. Varney,.
The current library building was built in 1907 (replacing the Morton Block),[3] designed by Alexander Wadsworth Longfellow, nephew of the poet Henry Wadsworth Longfellow, and is listed on the National Register of Historic Places.
The holdings are dedicated to the history of Maine and include books, archival material, maps, newspapers, photographs, as well as engineering and architectural drawings.
The library also collects on family history, specifically Maine, early New England and eastern Canada.
Topics for the changing exhibits include Maine's history, politics, culture, sports, religion, art, and business.