Born in Sonoma, California, Mary Henry studied 1933–34 at the California College of the Arts (then called the California School of Arts and Crafts) in Oakland, California, where her teachers included modernists Ethel Abeel, Glen Wessels, and Marie Togni. She won a prize in a printmaking contest sponsored by Iowa State University (Ames, Iowa), and was invited there to teach applied art in their home economics department. Her "childhood sweetheart" Wilbur Henry "reluctantly" agreed to marry her and accompany her to Iowa, where he completed a master's degree in entomology while she taught.