During the Middle Woodland Period, two thousand to one thousand five hundred years ago, Ohio's American Indian cultures began to quarry Flint Ridge flint on a more industrial scale. They continued to use the flint to make tools for daily living, but they also began to create specialty items such as bladelet cores and teardrop-shaped knives. These were signature artifacts of the Hopewell culture, from one through four hundred fifty C.E., and Hopewell people used them as burial offerings, ceremonial gifts, and trade items distributed from special places such as the Newark Earthworks. After the decline of the Hopewell culture, later residents focused on tool materials closer to their homes, and the use of Flint Ridge flint fell sharply. When Europeans introduced their trade goods to American Indians in the seventeen hundreds, Flint Ridge was all but abandoned. For a brief period from the eighteen hundreds to the nineteen twenties, however, European Americans quarried Flint Ridge flint to make millstones and sandpaper.