I bet it's a home made graduation or bridesmaid dress made from yardage intended for home furnishings. The name, date and print colour register are all along the selvedge. There were scads of these big jewel tone prints around then. There used to be a store in Toronto called B.B. Bargoons, and they sold yards and yards of these dark vaguely historic floral prints. Rooms full of ruffle edged tablesloths, bed skirts and curtains made from these Victorian-inspired printed cottons always reeked of potpourri!