The objective of this research was to introduce a workable longwall mining system into the Illinois No. 6 Seam. Earlier attempts at longwall mining in the Illinois Basin had failed owing to inadequate ground control by chock-type roof supports available in the 1960's. As a result of a cost-sharing agreement between the Bureau of Mines and the Old Ben Coal Company in 1975, longwall mining was demonstrated in Old Ben No. 24 Mine. The use of shield-type roof supports instead of chock-type roof supports appears to be the major factor contributing to successful roof control. Some of the advantages of shield-type roof supports are the short span of exposed roof, quickly applied support, stability of the structure, and full shelter for face personnel. The longwall at Old Ben No. 24 Mine was experimental in nature. Longwall productivity surpassed that of room-and-pillar mining, but not to a spectacular degree; however, subsequent longwalls at Old Ben Coal Company mines were five times more productive.