The Smithsonian is currently building a National Museum of the American Latino. In the meanwhile, they occupy an exhibit space within National Museum of American History. This website includes information about their exhibits and plans for expansion as well as digital guides to their holdings.
The Hispanic Reading Room at the Library of Congress hosts events, conversation, exhibits (both digital and live), and generates resources related to Latin American history and culture.
One of the best archival collections on Latin American/ Latino Studies. Includes many digitized materials from throughout the Americas, as well as research guides and links to additional resources.