Sewing Machine Patent model, Improvement in Sewing Machines, 1873. Helen A. Blanchard, of Boston, Massachusetts. Patent No. 141987 Issued August 19, 1873. This patent model for an improvement in sewing machines introduced the buttonhole stitch. Blanchard received some twenty-eight patents, many having to do with sewing. She is best remembered for inventing the zigzag overstitch sewing machine.
National Museum of American History