During the blockades of the Revolution, the War of 1812, and the Civil War, it became necessary for North Carolina to convert its gristmills to saltworks. Windmills were used to pump sea water into the plant, where it was then either boiled or evaporated, leaving only salt residue. Toward the end of the Civil War, several saltworks were destroyed by Yankee forces. So far, only thirteen saltworks that used windmills in production have been identified. They are in New Hanover, Carteret, and Brunswick counties.