What major discovery is Christopher Columbus credited with in 1492?

Christopher Columbus is credited with the discovery of the Americas in 1492 because he made his first voyage across the Atlantic Ocean and landed in the islands of the Caribbean, particularly on an island that is often identified as part of the present-day Bahamas. Although he did not reach the mainland of North America on this first voyage, his expeditions initiated widespread awareness of the existence of the American continents among Europeans.

Columbus's voyages did not lead him to India, which was not reached until later by other explorers who found alternate routes. Likewise, he did not discover the Pacific Ocean; this body of water was encountered later by explorers such as Vasco Núñez de Balboa. Similarly, he never reached Australia, which was discovered and explored by European navigators much later in the 17th century. Thus, the significance of Columbus lies primarily in his role in bringing the Americas to the attention of Europe, fundamentally altering the course of global history and eventual colonization.