This Thursday marks the 233rd anniversary of the signing of the U.S. Constitution. Constitution Day and Citizenship Day are recognized together, as described in 36 U.S.C. § 106(b) to "commemorate the formation and signing on September 17, 1787, of the Constitution and recognize all who, by coming of age or by naturalization, have become citizens."
While the restricted library building access and quarantine protocols mean we can't provide our usual pocket Constitutions to visitors for the time being, the Government Publishing Office's Constitution of the United States with Index and the Declaration of Independence, Pocket Edition is available as House Doc. 112-129 (be sure to select "Booklet" if printing!). The text of the Constitution is also available in the Organic Laws of every print or electronic version of the U.S. Code, in the Library of Congress's Constitution Annotated site, and as a high-quality scan at the National Archives.
To learn more about the history behind the drafting and signing of the U.S. Constitution, try a search of the Duke Libraries Catalog for the subject heading "United States. Constitution -- Signers -- Biography." Although print materials are available for contactless Takeout requests, you can also use the "Available Online" filter to limit to electronically available texts. E-books containing biographical sketches of the Framers include John R. Vile's The Men Who Made the Constitution: Lives of the Delegates to the Constitutional Convention and the 1986 NARA publication Framers of the Constitution. An electronic version of Janice McKenney's Women of the Constitution: The Wives of the Signers is also available. This title expands upon a classic 1912 text "The Wives of the Signers," which can be found in Volume 3 of Pioneer Mothers of America (in HeinOnline).
For help with locating other U.S. constitutional law resources or with navigating print or online collections, be sure to Ask a Librarian.