The archive collection known for many years as the Human Studies Film Archive (HSFA) has recently changed its name to the National Anthropological Film Collection (NAFC). This forms part of the National Anthropological Archives within the Department of Anthropology of the National Museum of Natural History, which is one of the Smithsonian Institution museums.
The on-line catalogue of the NAFC can be accessed via the Department of Anthropology page. However, please note that once you have reached that page, it is necessary to scroll down and click on a box to the right where the NAFC is still identified under its old name, i.e. Human Studies Film Archives. You can access the Department of Anthropology page here.
In contrast to the American Museum of Natural History film collection in New York, the NAFC is entirely focused on films of ethnographic interest. It is also much more extensive. Among its holdings are an interesting collection of early films made by an eclectic range of filmmakers, including naturalists, explorers, missionaries, leisure travellers, an army doctor, and the Tamil art historian and philosopher Ananda Coomaraswamy, but also including footage gathered by the celebrated anthropologist Melville Herskovits and by the ethnomusicologist Laura Boulton.
Although there are plans to digitise the collection, most films have currently to be viewed on site, not at the main Museum of Natural History building in downtown Washington, but rather at the Museum Support Center in Suitland, Maryland (see above). This lies beyond the Beltway but can be reached relatively easily via the subway system.