 In October 1777, the British Parliament banned the importation of gunpowder into the rebellious American colonies.To supply the Overmountain Men, five hundred pounds of black powder was manufactured by Mary Patton and her husband at their Gap Creek powder mill in present-day Elizabethton.On the first night of the march from Sycamore Shoals, the Overmountain Men stored the Patton black powder in a dry cave known as "Shelving Rock" to protect it from the rain.