Claim: Christopher Columbus sailed across an ocean.

Christopher Columbus -LRB- Cristoforo Colombo -- 20 May 1506 -RRB- was an Italian explorer , navigator , and colonizer . A citizen of the Republic of Genoa , under the auspices of the Catholic Monarchs of Spain he completed four voyages across the Atlantic Ocean . Those voyages and his efforts to establish permanent settlements on the island of Hispaniola initiated the European colonization of the New World .   At a time when European kingdoms were beginning to establish new trade routes and colonies , motivated by imperialism and economic competition , Columbus proposed to reach the East Indies by sailing westward . This eventually received the support of the Spanish Crown , which saw a chance to enter the spice trade with Asia through this new route . During his first voyage in 1492 , he reached the New World instead of arriving at Japan as he had intended , landing on an island in the Bahamas archipelago that he named `` San Salvador '' . Over the course of three more voyages , he visited the Greater and Lesser Antilles , as well as the Caribbean coast of Venezuela and Central America , claiming all of it for the Crown of Castile .   Columbus was not the first European explorer to reach the Americas , having been preceded by the Viking expedition led by Leif Erikson in the 11th century , but his voyages led to the first lasting European contact with the Americas , inaugurating a period of exploration , conquest , and colonization that lasted several centuries . These voyages thus had an enormous effect on the historical development of the modern Western world . He spearheaded the transatlantic slave trade and has been accused by several historians of initiating the genocide of the Hispaniola natives . Columbus himself saw his accomplishments primarily in the light of spreading the Christian religion .   Columbus never admitted that he had reached a continent previously unknown to Europeans , rather than the East Indies for which he had set course . He called the inhabitants of the lands that he visited indios -LRB- Spanish for `` Indians '' -RRB- . His strained relationship with the Spanish crown and its appointed colonial administrators in America led to his arrest and dismissal as governor of the settlements on the island of Hispaniola in 1500 , and later to protracted litigation over the benefits that he and his heirs claimed were owed to them by the crown .