Oakland born Bonnie Cashin was indeed the mother of American Sportswear. She was among a small group of women who emerged as influential designers after World War II. Cashin believed that clothing should be practical and functional. In 1955, Cashin told a reporter, "Fashion evolves from need." She once described her designs as "articulating with the body." She traveled widely and drew heavily from her visits to Asia. The Japanese kimono was her inspiration for layering and detail such as wide sleeves. Her signature elements were mohair and fine suede, supple leather to pipe edges of coat sleeves and unusual closures such as metal toggles. She also designed purses for Coach. Her classic designs in the early 1960s included the shoulder bag and a clutch-style purse with a removable shoulder strap. It was Cashin who made a fashion garment out of the poncho, a style popular today. In the 1960s, she created oversized plaid ponchos with hoods in luxurious fabrics such as mohair and wool and teamed them with plaid, fringed skirts.

Among Cashin's pioneering designs were a turtleneck that did not require a zipper to get over the head, the kimono coat piped in leather, the hooded jersey dress, the jumpsuit, the snap-closed "pocketbook" pocket, canvas raincoats, soft knee-high boots and the use of industrial zippers. She is famous for her dog leash skirt: a long wool garment that could be instantly shortened by latching a small brass ring sewn at the bottom to a small brass clasp sewn into the waistline.