There are currently three formula dating techniques available to archaeologists studying 17th and 18th century sites using imported English clay tobacco pipe stems based on Harrington's histogram of time periods; Binford's linear formula, Hanson's formulas and the Heighton and Deagan formula. Pipe stem bore diameter data were collected from 26 sites in Maryland, Virginia, North Carolina and South Carolina in order to test the accuracy and utility of the three formula dating methods. Of the formulas, the Heighton and Deagan proved to be the most accurate, producing formula mean dates closest to the dates assigned to the sites using other dating techniques. It was also determined that all three formula dating methods work better in Maryland and Virginia than in North and South Carolina. Other aspects of pipe stem dating were explored in this paper including regional consumption patterns and the influences Dutch pipes have on formula dating. These questions were addressed specifically on sites from the Chesapeake. This analysis supports recent assertions that the Chesapeake should be split into two sub-regions, the Upper and Lower Chesapeake.  M.A