The new county was made from parts of three counties already established, Ste. Genevieve, Jefferson and Washington, and comprised . An article written by Sallie Burks Keith furnishes this interesting insight as to the method by which boundaries of the new county were established: "Mr. Carol Williams and three other men met at a point (supposedly the present Court House Square) and were to ride until six by the clock; one north, one south, one east and the other west. Where each stopped was to be the boundary line. Thus the irregular line."