The images in this category were published in the United States without copyright notice prior to 1978, which causes the work to be irrevocably in the Public Domain.

To place a file in this category, add the tag ((PD-Pre1978)) to the bottom of the file's description page. If you are not sure which category a file belongs to, consult the file copyright tag page. If this category is very large, please consider placing your file in a new or existing subcategory. Free files can be moved to the Wikimedia Commons.