In CMU Special Collections is a copy of the US Bill of Rights printed in Philadelphia by Francis Childs and John Swain. The document is undated, but is usually assigned to January or February 1792. This edition is a grail of Americana: it is the first appearance of the Bill of Rights in print following ratification in 1791. It is also perhaps the rarest item in Special Collections. Only five copies are known to survive: one at the Maryland State Archives, another at the American Antiquarian Society, and another at the Library of Congress. A fifth copy is in private hands and was last sold at auction in 2002. Special Collections’ copy is part of the Posner Memorial Collection, deposited with the Libraries in 1978 in memory of Henry Posner Senior (d. 1976), who purchased his copy from antiquarian bookseller H.P. Kraus in 1963.