The Maine Historical Society has been awarded a large grant that will be used to upgrade the organization’s storage capacity.

The $500,000 grant from the National Endowment for the Humanities will allow the society to install compact storage and consolidate its storage collections at a new Riverside Street site that has been developed with the Portland Public Library. That site provides climate-controlled storage space that will aid long-term preservation of museum and library collections, the society said.

The new site also has space for caring for, processing and digitizing the collections, the society said.

The society has a large collection of books, architectural documents, newspapers and other print publications, photographs and manuscripts from the 16th to the 21st centuries. It also has artifacts, including textiles, costumes, furniture, paintings, tools, industrial equipment and decorative arts.

The society owns and operates the Wadsworth-Longfellow House in Portland, the boyhood home of poet Henry Wadsworth Longfellow.

The society said developing a collections center is a critical step in efforts to improve its Congress Street facility and capacity as the organization approaches its bicentennial next year. About a quarter of the society’s museum holdings and 10 percent of the library’s collections have been moved to the new facility, which was opened in 2015.

The grant announced Monday was one of 30, totaling $13.9 million, awarded by the NEH in this round of its Infrastructure and Capacity Building grants program.