Included are 19 original architectural drawings and photographs and prints of drawings by Withers. Among these are designs for the Van Schaick Free Reading Room (now the Huntington Free Library and Reading Room), Bronx, N.Y.; reredos proposed for the Church of the Transfiguration, New York City; Chapel of the Good Shepherd on Blackwells Island (now Roosevelt Island), N.Y.; a competition design for the Cathedral of St. John the Divine, New York City; St. Thomas Episcopal Church in Hanover, N.H.); and drawings by others, including Sullivan Jones and Rowland Plumbe. This collection also includes manuscript copies of three letters from Withers to his mother written at sea in 1852 and describing his trip to America.

This collection includes Giorgio Cavaglieri's preliminary studies, working drawings, presentation drawings, and specifications, circa 1962-1965, for his renovation of the Jefferson Market Courthouse into a library. Also, prints of drawings, 1876, by Vaux and Withers for the original building, and drawings, circa 1918-1940, for alterations.