 By midsummer of 1730, a number of Pennsylvania Dutch settler families had crossed the river and taken up residence.Determined to counter this development, a Marylander, Thomas Cresap, opened a second ferry service at Blue Rock, about four miles (6 km) south of Wright's Ferry near current day Washington Boro, Pennsylvania.Owing to the royal proclamation of 1724, the Pennsylvania settlers did not have clear title to the lands that they occupied.