Cobb opened her first
Manhattan manicure salon in 1878 as "Mrs. Pray's Manicure". The Salon was an extension of her husband's manufacturing business. Over time Cobb developed a savvy business manner and focused on a higher-end market that evolved into operations at two townhouses on West 23rd street in New York and branches in Chicago, Washington, Boston and Philadelphia. In addition to manicures, Cobb's salons offered hairdressing and skin care. In 1884 Mary E. Cobb and J. Parker Pray divorced, and by court order Mary retained custody of her children and proprietorship of the business, and reverted to her maiden name as Mrs. Mary E. Cobb. In that same year she and her ex-husband made their most lasting contribution to the nail care industry with the invention of the
emery board. After her 1884 divorce she expanded into manufacturing, producing her own line of cosmetics, nail care products, powders, and a steam facial machine. She began to tap into a wider emerging market, selling these products in new major
department stores and smaller
five and dime shops. In addition to retail outlets, Cobb targeted a mail order base and also offered to professionally train women in the nail care trade as a form of expansion. ==Later years==