Beginning in the mid to late 19th century, farmers produced grain crops beyond the needs of their families, while industry created demand for the surplus. The first facilities for receiving and storing grain were flat storage warehouses that held grain in sacks or barrels. By the beginning of the 20th century, greater productivity and demand required new technology to handle and move large amounts of grain quickly. Grain elevators were developed to receive, weigh, store, and transfer grain in bulk quantities. Early small-town elevators used working equipment such as vertical bucket conveyors called grain legs to lift grain to storage bins, mills to remove chaff and foreign materials and clean the grain, and scales to determine the quantity of grain for which a farmer would be paid. Grain elevators and their employees played a valuable role in the advancement of agriculture and in the lives of farm families.