Before its coastline was explored by Europeans in the 16th century, Delaware was inhabited by several groups of Native Americans, including the Lenape in the north and Nanticoke in the south. It was initially colonized by Dutch traders at Zwaanendael, near the present town of Lewes, in 1631. Delaware was one of the 13 colonies participating in the American Revolution. On December 7, 1787, Delaware became the first state to ratify the Constitution of the United States, and has since been known as "The First State". Since the turn of the 20th century, Delaware is also a "de facto" onshore corporate haven, in which by virtue of its corporate laws, the state is the domicile of over 50% of all NYSE-listed business and 60% of the "Fortune" 500.