These are photographs of the Adams Building that I took from the 6th floor of the Madison Building. People on the street looking up at the building don’t see all of the levels clearly, but the overall shape of the building is clearer from this perspective. It seems to be similar to that of a mastaba or step pyramid, a form used by ancient Egyptians for early tombs or a ziggurat – a religious building built in ancient Mesopotamia. Both have successively receding stories or levels.
When the Adams Building was designed and built, Art Deco was in fashion as a result of the 1925 Exposition Internationale des Arts Décoratifs et Industriels Modernes (International Exposition of Modern Decorative and Industrial Arts). Motifs from the ancient world, including Egypt and Mesopotamia, were incorporated in many different decorative items from jewelry to pottery. In the case of the Adams Building, it would have made sense if the architects had looked to ancient architecture for inspiration.
Libraries trace their history back to the Ancient Library of Alexandria so looking to ancient Egypt for inspiration for this new Library of Congress building – then called the Annex would have made sense. However, since ziggurats are considered temples and libraries are often considered temples of knowledge, it may be more likely that they were the inspiration.