The portion of Delaware in which South Bethany lies was subject to a lengthy legal dispute, "Penn vs. Baltimore", that broke out in 1683, as to whether the land belonged to the Province of Maryland or the Province of Pennsylvania. While it dragged on, William Penn granted the Delaware Colony its own legislature in 1701, establishing it as a separate colony. The dispute over the boundaries of the three colonies was not resolved until 1759, when the parties to the dispute agreed that the area where South Bethany now lies was part of Delaware.