Here is a list of National Park Service websites that pertain most closely to archeology and anthropology.
The Library has some of the National Park Service's publications in these areas, especially if they pertain to sites in Texas or the Southwest. Here are some NPS series (note that Library has substantial holdings only in the Handbooks series):
Some of these items may have online versions. If so, there will be links to these digital documents in the Library Catalog, or you can search for them on the National Park Service website.
Here is a list of Smithsonian Institution's websites that pertain most closely to archeology and anthropology.
The Library only has selected items in print from these Smithsonian series, but there are links to digital versions in the Library Catalog:
There are other agencies that provide access to materials. Some selected websites include:
The library owns other historic information produced by the Congress, the Library of Congress, and various federal agencies. Some examples include the following:
The Library has several books detailing the history of important government buildings in Washington. These sets are also available via govinfo.gov.