The Margaret McCollum papers date from 1942 to 2008 and measure 4.5 linear feet. The papers are arranged in six series: Biographical Information, Personal Correspondence, Des Moines City Council, American Association of University Women (AAUW), Parent Teacher Association (PTA), and American Mothers, Inc (AMI). The collection was kept in the chronological order in which McCollum herself arranged it. It illustrates the political and community work in which McCollum was involved as well as daily activities and family life in the second half of the twentieth century.

The Biographical information series (1967-2004, and undated) contains McCollum's 1994 resume, which describes her educational background, professional experiences, family, civic activities, and honors and awards. Also included are letters from two of her children supporting her 1967 nomination as University of Iowa Representative Mother, her acceptance speech and a newspaper article on that award, a photograph of the McCollum family, and current articles on the activities of McCollum and her husband. Hard copies of emails sent by McCollum to family members containing transcriptions of her mother's notes from a 1920 trip to Europe complete the series.

The Personal Correspondence series (1942-2002) contains the Christmas and family letters written by McCollum and her husband which kept the entire family up to date on family news and events.

The Des Moines City Council series (1973-1974) contains correspondence, newspaper articles, and pamphlets from McCollum's campaign and the time she spent in office.

The American Association of University Women (AAUW) series (1959-1996) contains general materials from the national organization such as newsletters, correspondence, and brochures, as well as materials specifically related to the Des Moines branch such as bylaws and meeting minutes. Correspondence written by McCollum during her presidency of AAUW, and three manuals that consist of AAUW guidelines and directories complete the series.

Most of the Parent Teacher Association (PTA) series (1953-1980) consists of documents McCollum collected during the late 1950s and early 1960s when she served as president of the Des Moines Council of Parents and Teachers and board member of the Iowa Council of Parents and Teachers. These include newsletters, correspondence, newspaper articles, and notes taken at the 1959 State Convention, which are contained in the Iowa Council of Parents and Teachers folder.

Nearly half of the materials of this collection are located in the American Mothers, Inc. (AMI) series (1969-2002). They document McCollum's work as a board member and treasurer of the national organization, and also include materials related to the state affiliate, Iowa Mothers Association, of which McCollum was president in 1973. Handbooks, newsletters, and other materials published by AMI complete the series.