The Archives of American Art is the largest collection of primary resources documenting the history of the visual arts in the United States. More than 16 million items of original material are housed in the Archives' research centers in Washington, D.C. and New York City. It was established in 1954
As a research center within the Smithsonian Institution, the Archives houses materials related to a broad variety of American visual art and artists. All regions of the country and numerous eras and art movements are represented. Among the significant artists represented in its collection are Jackson Pollock, Lee Krasner, Marcel Breuer, Rockwell Kent, John Singer Sargent, Winslow Homer, John Trumbull, and Alexander Calder. In addition to the papers of artists, the Archives collects documentary material from art galleries, art dealers, and art collectors. It also houses a collection of over 2,000 art-related oral history interviews and publishes a bi-yearly publication called Archives of American Art Journal which showcases collections within the Archives.
More information on the Wikipedia page 
The website is .