Many contemporary inventors attempted to develop a design that would process short staple cotton, and Hodgen Holmes, Robert Watkins, William Longstreet, and John Murray had all been issued patents for improvements to the cotton gin by 1796.[12] However, the evidence indicates Whitney did invent the saw gin, for which he is famous. Although he spent many years in court attempting to enforce his patent against planters who made unauthorized copies, a change in patent law ultimately made his claim legally enforceable – too late for him to make much money from the device in the single year remaining before the patent expired