This material relates to Alexander B. Grosart's biography of Wilson. There are notes and copies of letters and documents, including a copy of Wilson's will. There is one poem by Wilson, "The Last Wish," and an 1806 letter to William Bartram.

This collection is principally letters to Collinson about seeds, plants, and gardens from seed cultivators and owners of country estates, including Cadwallader Colden, John Hanbury, Lord and Lady Petre, the Duke of Norfolk, the Duke of Richmond, Sir Hans Sloane, and Daniel Solander. There are also several letters of John Bartram to William Bartram and Philip Miller.