OHMAR’s roots can be traced to the oral history luncheons sponsored first by Martha Ross and later by Mary Jo Deering at George Washington University. A workshop and luncheon on March 19, 1976, attracted 133 people, including students in oral history classes and representatives of projects and institutions in Washington, D.C., and nearby states. Afterwards, eighteen people remained to discuss the possibility of establishing a regional oral history association. Another meeting took place two months later at Towson State College, and in June 1976 OHMAR was formally organized at a meeting at the Community College of Baltimore. “We called ourselves Oral History in the Mid-Atlantic Region,” said Martha Ross, “possibly because we thought that made a more seductive acronym (OHMAR) than the alternative, Mid-Atlantic Oral History Association (MAOHA).

On October 9, 1976, OHMAR held its first meeting, hosted by Joan Anderson at the Community College of Baltimore. Ben Frank was elected president, and Betty Key and Theodora Poletis were designated to draft a constitution. In December 1976 OHMAR published its first newsletter. Aided by a grant from the Maryland Bicentennial Commission, OHMAR sponsored its first all-day workshop in March 1977 at the Community College of Baltimore.

Initially, OHMAR designated the states of Delaware, District of Columbia, Maryland, New Jersey, Pennsylvania, Virginia and West Virginia as the Mid-Atlantic Region. In 1987 OHMAR expanded its boundaries to include New York in its membership region.