The Marianne Michael papers date from 1897 to 2005 and measure 3.13 linear feet. The papers are arranged in nine series: Photographs, Biographical, Professional, Writings, Correspondence, Garkida, Nigeria, Church of the Brethren Conferences, Elizabeth Michael, and Genealogy.

The Photographs series consists primarily of black and white photographs taken during the Michaels' missionary work in Garkida.

The Biographical series includes diaries, various clippings and certificates earned by Marianne Michael, dating from 1928-2003.

The Professional series includes documents related to Michael's job as a social worker at the University of Iowa. These encompass her M.A. thesis, entitled "Factors Related to the Use of the Food Commodity Program by ADC Recipients in Iowa, 1961", professional publications from 1970-1981, various talks from 1981-1999, a scrapbook from the National Association of Perinatal Social Workers annual meeting in 1985, job evaluations dating from 1964-1987, salary letters and grades from 1964-1987, and correspondence associated with Michael's retirement in 1987.

The Writings series includes Michael's religious publications and talks from 1949-1990, a small collection of letters to the editor written in Iowa City from 1964-2005, drafts of her religious publications, two logs of Michael's day-to-day experiences from 1948-1956 and from 1957-1986; and two memoirs written by Michael, one detailing a trip to the United States from Nigeria in 1956, and one which begins with her birth in 1917 and continues through 1999.

The Correspondence series includes letters to friends and family from 1944-2000, the annual Michael family newsletters from 1964-1998, a large collection of letters and documents from Marianne Michael's mother, Helen Krueger Trent from 1927-1980, a few letters from Zola Krueger, Michael's sister-in-law, a small collection of letters from the Michaels' eldest daughter Rosemary from 1956-1984, a few letters from Clara Miller, a friend and quilting companion dating from the mid-1970s, and an incomplete collection of the Round Robin letters circulated among Marianne Michael and her college friends from 1979-2001.

The Garkida, Nigeria series contains correspondence between the Michaels and their relatives and correspondence between the Michaels and family friends, the Vaughns, dating from 1948-1961. It also includes some miscellaneous correspondence, an undated diary kept by Marianne Michael during her missionary work in Garkida, documents relating to the women's literacy group developed by the Michaels, and notes from the Sunday school lessons taught by Michael in Garkida.

The Church of the Brethren Conferences series includes travel brochures, correspondence, and conference programs from two church conferences: the annual meeting held in Portland, Oregon in 1991 and the National Older Adult Conference held in Lake Junaluska, North Carolina in 1996.

The Elizabeth Michael series includes a chronology of Elizabeth Michael's life written by her mother Marianne Michael, a lock of Elizabeth's hair from 1959, schoolwork and artwork from Hillcrest Boarding School in Nigeria in the late 1950s to the early 1960s, and from Iowa City Public School system from the early 1960s to the early 1970s. Also included is a large collection of letters written by Elizabeth Michael to her parents dating from 1967-2000. These correspondence include four folders of undated letters and one folder of letters which can be approximately dated based on Elizabeth Michael's city of residence.

The Genealogy series includes three published genealogies written by Marianne Michael: "Robert McLellan: Iowa Pioneer Farmer" (1996) is accompanied by three folders of the documents used as illustrations in this work, "An Aschenbrenner Family: Hesse to USA" (1998), "The Jacob George Family of Adams County, Pennsylvania" (1998), and "Out of Ebern: A Michael Family History" (2001).