Mary Gehman has actively participated in the New Orleans writing community since the 1970s. She was greatly involved in developing Margaret Media, Inc., which was established in 1981 in New Orleans as the publisher of Distaff, a women's monthly newspaper first published in 1972.

Although the newspaper, the only one of its kind in the Deep South, ceased publication in 1982, the company president and one of Distaff's founders, Mary Gehman, continued to operate Margaret Media, Inc. to conduct women's history tours of the French Quarter and eventually to publish the book <i>Women and New Orleans</i> in 1988. Her second book, <i>The Free People of Color of New Orleans</i>, was published in 1994, and the third, <i>Louisiana's Great River Road: The Mississippi from Angola North to Venice South in 2003</i>.

The company expanded to other authors by publishing <i>Gumbo People</i> by Sybil Kein in 1999, a volume of poetry and songs in the Louisiana Creole language which is still spoken in some parts of the state.

For researchers Gehman keeps data bases and extensive files on people and issues involved in her research and writing. She is interested in sharing these on a limited basis with colleagues. These are personal files and not available on the Internet or in institutional archives. The press Margaret Media. Inc. continues to publish works related to Louisiana and New Orleans history and culture. After the home of Gehman and the office of Margaret Media flooded in Hurricane Katrina in August 2005, Gehman stayed in New Orleans, but in June 2006 she retired from teaching English at Delgado Community College and relocated to a house in the historic district of Donaldsonville, LA, 55 miles upriver from the Crescent City. She maintains close business and social ties to New Orleans.