The collection consists of papers of Wilcox, including correspondence, diaries (various years from 1940-1979), typescripts of his published and unpublished short stories, articles, literary criticism, and novels, photographs, and printed material. There are approximately 95 short works, primarily from the 1930s-1940s, such as "Mother of a Hero" anmd "Night Falls in Michigan," as well as manuscripts for his published novel Everything is Quite All Right (1945) and three other novels, The Color of Darkness, Rock Me to Sleep, and Helen. Correspondence includes 46 letters (1934-1959) from Alice B. Toklas, five from Gertrude Stein, several from Thornton Wilder, Samuel M. Steward, August Becker, Gertrude Abercrombie, and other writers and friends. Also present is an extensive correspondence between Wilcox and his wife, Esther Willson Wilcox, spanning their courtship, marriage (1931), and his trip to Paris in 1950. Their home was in Chicago, Illinois.

In addition, there are over 400 photographs of Wilcox, his wife and their relatives, Alice B. Toklas, Sam Steward, James Purdy, and others. Printed material includes such magazines as Creative Writing, The New Yorker, Decade, and Story which contain works by Wilcox.