The collection contains a sizable body of letters to Dwight from friends and publishers, as well as a group of letters from Dwight to several other friends. Also there are manuscripts of some of the articles he wrote for magazines and one of the projected books he worked on about L'Enfant, the planner of the city of Washington, DC. There is a miscellaneous section that contains various items of interest, such as family photographs, notes, etc.

Well known persons included in the correspondence (letters to Dwight) include John Dos Passos (4 letters), Gilbert Grosvenor, Willa Cather (13), Stark Young, Arnold Toynbee (5), Alice B. Toklas (3), Otis Skinner, Harold J. Laski (1), Archibald MacLeish (1), Edith Wharton (3), William Dean Howells (2), President Calvin Coolidge (1), President Herbert Hoover (1), Eleanor Roosevelt (1), Wendell Wilkie (1), Hugh Wiley (5), Talcott Williams (4), and Willa Cather to Mary Willard (2) (December 25, 1941 and Jan. 10, 1942, in letters to Dwight). Other correspondents are much more prolific, having as many as twenty to thirty letters in some cases.

This collection is organized into five series:

• 1. Correspondence, 1893-1959
• 2. Printed articles, 1925-1940
• 3. Manuscripts, 1890-1926
• 4. Notebooks and Diaries, 1897-1959
• 5. Miscellaneous, 1898-1958