People only figured out the mechanics of plate tectonics relatively recently. However, they started noticing that the continents looked like they had fit together as soon as they had accurate maps to look at. In the late 1500's
Abraham Ortelius in his work Thesaurus Geographicus … suggested that the Americas were "torn away from Europe and Africa … by earthquakes and floods" and went on to say: "The vestiges of the rupture reveal themselves, if someone brings forward a map of the world and considers carefully the coasts of the three [continents]."