Among the books in Thomas Jefferson's Library that Congress purchased in 1815 was a copy of William Cheselden's The Anatomy of the Human Body, and Jefferson's annotations show that he studied the text carefully, connecting it to his study of ancient literature and history.
The Library of Congress owns two copies of the first printing of the Declaration of Independence, also known as the Dunlap Broadside, printed in Philadelphia on the evening of July 4 and the early morning of July 5, 1776. One copy was George Washington's, and the other came to the Library from collector Peter Force.