 Europeans came to the Delaware Valley in the early 17th century, with the first settlements founded by the Dutch, who in 1623 built Fort Nassau on the Delaware River opposite the Schuylkill River in what is now Brooklawn, New Jersey.The Dutch considered the entire Delaware River valley to be part of their New Netherland colony.In 1638, Swedish settlers led by renegade Dutch established the colony of New Sweden at Fort Christina (present-day Wilmington, Delaware) and quickly spread out in the valley.