Complex sentence: The western portion of Long Island was settled by the Dutch (giving it the name Lange Eylant), while the eastern region was settled by English Puritans from New Haven, Connecticut, settling in Southold on October 21,1640.
Split into simpler sentences: The western portion of Long Island was settled by the Dutch, who named it Lange Eylant. The eastern region was settled by English Puritans from New Haven, Connecticut, who arrived in Southold on October 21,1640.