Salt was used to "cure" or preserve meat and fish to keep it from spoiling. At Mount Vernon, large quantities of meat and fish were salt-cured to feed family, guests, servants, and slaves throughout the year.  The salt house was kept locked to prevent theft.  The seines, or large nets, hanging on the walls would have been used by George Washington's slaves to farm the Potomac River every spring when the fish were running. The catch, mostly shad and herring, were then salted and stored in large barrels to preserve them for sale and for use on the plantation. It was common for the slaves to catch over 1,000,000 fish in a six-week period!

Once the fish had been caught and preserved, Washington shipped and sold it to markets along the east coast of America and in the West Indies. Fish was also an important part of the diet of the Mount Vernon slaves.