{"value"=>"<p>This series, dating from 1842 to 2012 and compiled by Mattson, is composed of bookmarks, commemorative coins, photographs, flyers, theater and dance programs, ink drawings, cigar signs, letters, greeting cards, stickers, stamps, comics, art, subway cards, postcards, journal and newspaper clippings, notes, catalogs, tickets, a speech transcript, and commemorative brochures from societies, schools, events, and landmarks associated with Whitman. The series retains Mattson's groupings by binders, journal and newspaper clippings, folders, and scrapbooks. Most of the items date from the 1960s to the 1990s and are connected tenuously to Whitman. Items in the series range from bookmarks, brochures, flyers, and photographs of Whitman's birthplace to a condition book from the 1962 Walt Whitman Stakes. The series includes Mattson's notes on Whitman and reflects his collecting efforts.</p>"}