The primary holdings are extensive collections of original drawings, proofs, and tear sheets of Milton Caniff's comic strips and illustrations, audio/visual materials, correspondence files, business accounts, research files, awards, scrapbooks, and realia. The collection has significant holdings of original art and reproductions of Mister Gilfeather, The Gay Thirties, Dickie Dare, Terry and the Pirates, Male Call, Steve Canyon, and illustrations done for the Columbus Dispatch and the Associated Press.
The Correspondence series includes letters to and from Milton Caniff from fans, cartoonists, business associates, family members, and friends. Also included are correspondence and materials regarding organizations and clubs with which Milton Caniff was associated, publicity materials, and articles by and about Milton Caniff.
The Research Material series includes clipping files from magazines and newspapers, film stills and programs, model airplanes, informational publications, and military items used as reference by Caniff for his comic strips and other projects he undertook such as United States armed forces insignia designs.
The Business Records series contains bank statements, syndicate statements, income tax information, cancelled checks, check stubs, ledgers, bills, expense lists, drafts of wills, subscription notices, and household inventories.
The Photographs series includes photographs of Milton Caniff at chalk talks, in his studio, at personal appearances, at his home, and with organizations, family members, and cartoonists.
The Awards series includes awards, citations, proclamations, and certificates given to Milton Caniff from various organizations.
The Memorabilia and Merchandise series contains personal effects of Milton Caniff, Esther Parsons Caniff, and John Caniff, Milton Caniff's father; merchandise for comic strips Terry and the Pirates and Steve Canyon, and art and office supplies.
The Audio/Visual Material series includes promotion and personal film reels, Steve Canyon television show reels, Terry and the Pirates radio broadcasts, slides, and audio casette tapes.
The Scrapbook series contains scrapbooks with material and artwork for Milton Caniff's 75th birthday, newspaper clippings and publicity, awards and citations, personal photographs, and original artwork by Milton Caniff and Noel Sickles.