The document summarizes early European exploration of North America. It notes that the Vikings were the first to visit North America around 1000 AD, with colonies in Greenland and Iceland. It then discusses factors that made Europe ready to explore, including improved shipbuilding and new navigation instruments. It provides details on Columbus' first voyage in 1492, when he sailed for two months thinking he reached Asia but actually found the Americas, first landing on an island he named San Salvador. The document also briefly mentions Amerigo Vespucci proving Columbus had found a new world, with the lands being named America after him.