MAP 4.1 Frontier Settlements and Indian Towns in Pennsylvania, 1700–1740 German and Scots-Irish immigrants to Pennsylvania mingled with Indian settlements in the early eighteenth century as Delaware and Shawnee groups were pushed west from New Jersey. In the 1720s and 1730s, however, European migration escalated dramatically in the fertile river valleys. In response, once-independent Indian tribes joined the Delaware and Shawnee nations to strengthen their position against the influx of colonists.