Correspondence, manuscripts, diaries, commonplace books, drawings, photographs, and printed materials. The collection is a comprehensive documentation of the dramatist's career and includes manuscripts, typescripts, notes, and costume and scenic design for more than seventy of his plays and related writings; 31 diaries, commonplace books, and scrapbooks containing manuscript and typescript notes, travel sketches, original drawings, and photographs; and correspondence files including letters from Harley Granville-Barker, Sir Herbert Beerbohm-Tree, John Galsworthy, Booth Tarkington, and Thornton Wilder. Austin Strong's mother, Isobel Field, was the step-daughter of Robert Louis Stevenson. Consequently, the collection contains much Stevensoniana, including photographs and Isobel Field's letters from Western Samoa, where she was known as "Teuila." Also, correspondence and photographs relating to Cornwall Park, Auckland, New Zealand, which was designed by Austin Strong.