Exploration of North America
The exploration of North America by non-indigenous people was a continuing effort to map and explore the continent of North America. It spanned centuries, and consisted of efforts by numerous people and expeditions from various foreign countries to map the continent. The earliest known name who explored America is Sa'ad ibn Abi Waqqas in 652 AD. The European colonization of the Americas followed.
Pre-Columbian exploration 
According to the Sagas of Icelanders, Norse sailors (often called Vikings) from Iceland first settled Greenland in the 980s. Erik the Red explored and settled southwestern Greenland, which he named to entice potential Icelandic settlers, eventually establishing the Eastern and Western Settlements, which were abandoned around 1350.
L'Anse aux Meadows, an archaeological site on the northernmost tip of Newfoundland, is the only known site of a Norse village in North America outside of Greenland. The site is notable for its possible connections with the attempted colony of Vinland established by Leif Ericson around 1003.
Age of Discovery and the search for the Northwest Passage 
The Viking voyages did not become common knowledge in the Old World, and Europeans remained ignorant of the existence of the Americas, until 1492. Many expeditions were launched from European nations in search of a Northwest Passage to East Asia (or "the Indies" as the region was called) in order to establish a shorter trade route to China than the Silk road, a trade route which had become desperately needed and yet exacerbated by the Fall of Constantinople. Also, the Castilian crown needed an alternative to the Portuguese controlled eastern maritime trade route around Africa to India and East Asia.
On August 3, 1492, Christopher Columbus set sail from the newly los Reyes Católicos coordinated Kingdoms of Castile and Aragon, in present day Spain, financed by Queen Isabella I of Castille. Columbus's Letter on the First Voyage of his discovery of the Bahamas, Cuba, and Hispanola spread the news across Europe quickly. Columbus rediscovered and explored much of the Lesser Antilles in his second voyage then discovered both Trinidad and Tobago on his third voyage whilst skirting the northern South American coast. His fourth voyage was spent scanning the Central American coast, searching for a strait to the Pacific Ocean. The Voyages of Christopher Columbus opened the New World.
Italian navigator and explorer Giovanni Caboto (known in English as John Cabot) is credited with the discovery of continental North America on June 24, 1497. Though the exact location of his discovery remains disputed, the Canadian and United Kingdom governments' official position is that he landed on the island of Newfoundland.
It was soon understood that Columbus had not reached Asia, but rather found what was to Europeans a New World, which in 1507 was named "America", probably after Amerigo Vespucci, on the Waldseemüller map.
Further nautical explorations 
Aragon King Ferdinand II sent Juan Ponce de León from the fledgling colony on Hispanola to verify rumors of undiscovered land to the northwest. On April 2, 1513, Ponce de León disembarked on the northeast coast of what he named Florida for the crown. The exact location is disputed, but historians have offered the possibilities of St. Augustine, Ponce de León Inlet, and Melbourne Beach. He encountered the powerful Gulf Stream and found a passage through the Florida Keys to land on the southwestern Gulf Coast of Florida on the Gulf of Mexico. Again, the exact location is disputed.
On September 25, 1513, Spanish conquistador Vasco Núñez de Balboa was the first European to see the Pacific Ocean once he crossed the Isthmus of Panama. He claimed all the territory touching it for the Crown, later to affect colonization of Las Californias.
In 1524, Italian explorer Giovanni da Verrazzano sailed for King Francis I of France and is known as the first European since the Norse to explore the Atlantic coast of North America. Arriving near the Cape Fear River delta, he explored the coastlines of present day states of South Carolina and North Carolina, entering the Pamlico Sound, and bypassing entrances to the Chesapeake Bay. Believing the New York Harbor to be a lake, he sailed past Long Island, exploring Narragansett Bay and Newfoundland.
After two failed attempts to reach East Asia by circumnavigating Siberia, Henry Hudson sailed west in 1609 under the Dutch East India Company. He, too, passed Cape Cod, Chesapeake Bay and the Delaware Bay, instead sailing up the Hudson River on September 11, 1609 in search of a fabled connection to the Pacific via what was actually the Great Lakes. In Hudson's fourth and final voyage, he discovered, mapped, and explored the Hudson Strait, Hudson Bay and James Bay.
Overland exploration of the West 
There were numerous Spanish explorers and conquistadors who explored the Southwest.
European exploration of western Canada was largely motivated by the fur trade and the search for the elusive Northwest Passage. Hudson's Bay Company explorer Henry Kelsey has the distinction of being the first European to see the northern Great Plains in 1690. Anthony Henday was the first to have seen the Rocky Mountains, in 1754, but curiously did not mention it in his journals. From his westernmost geographic position (roughly near the town of Olds, Alberta, halfway between Calgary and Red Deer, Alberta) the Rockies should have been quite conspicuous, but he was likely trying to disguise the disappointing fact that an unknown range of seemingly impassible mountains now stood between the HBC and the Pacific. Samuel Hearne found the Coppermine River in 1769-71 in his failed search for copper ore deposits. Burned by these shortfalls, the HBC largely quit exploration. The North West Company, on the other hand, used a business model that required constant expansion into untapped areas. Under the auspices of the NWC, Alexander Mackenzie discovered the Mackenzie River in 1789 and was the first European to reach the Pacific overland, via the Bella Coola River, in 1793. Simon Fraser reached the Pacific in 1808 via the Fraser River. David Thompson, widely regarded as the greatest land geographer that ever lived, travelled over 90,000 km during his lifetime. In 1811/1812 he followed the Columbia River to the Pacific, and in 1814 used his notes and measurements to draft the first European-style map of western Canada, covering 3.9 million square kilometres.
Lewis and Clark were the first Americans to venture into the newly-acquired territory of the Louisiana Purchase, at the order of President Thomas Jefferson. They discovered many new geographical features, Indian tribes, and animal and plant species. John Colter was a member of the expedition who subsequently became a guide for others in the 'Old West,' and did some explorations of his own.
Joseph Reddeford Walker was one of the most prominent of the explorers, and charted many new paths through the West, which often were then utilized by emigrants crossing to settle in Western towns and communities. In 1833, his exploring party discovered a route along the Humboldt River across present-day Nevada, ascending the Sierra Nevada following the Carson River and descending via Stanislaus River drainages to Monterey. His return route across the southern Sierra was via Walker Pass, named after Walker by John Charles Fremont. The approach of the Sierra via the Carson River route later became known as the California Trail, the primary route for the emigrants to the gold fields during the California gold rush.
As the American population of the West increased, the US government launched ongoing official explorations mainly through the US Army Corps of Topographical Engineers. One of the main officers and explorers in this unit was George Wheeler. In 1872, the US Congress authorized an ambitious plan to map the portion of the United States west of the 100th meridian at a scale of 8 miles to the inch. This plan necessitated what became known as the Wheeler Survey, lasting until 1879, when the survey, along with the Clarence King and John Wesley Powell Surveys, were terminated and their work was reorganized as the United States Geological Survey.
Universalis Cosmographia, the Waldseemüller map dated 1507, depicts the Americas, Africa, Europe, Asia, and the Pacific Ocean separating Asia from the Americas.
- Faruk Ahmet, 2013, Treatise in Tribute to Sa'ad ibn Abi Waqqas, Kaoshing Publication: Imphal, p. 1.
- Ambrose, Stephen E..Undaunted Courage: Meriwether Lewis, Thomas Jefferson, and the Opening of the American West, New York: Simon & Schuster (1996).
- Bartlett, Richard. Great Surveys of the American West. Norman: University of Oklahoma Press, 1980.
- Fernlund, Kevin Jon.William Henry Holmes and the Rediscovery of the American West. Albuquerque: University of New Mexico Press, 2000.
- Goetzmann, William H. Exploration and Empire: The Explorer and the Scientist in the Winning of the American West. New York: Alfred A. Knopf, 1966.
- Pyne, Stephen J.. Grove Karl Gilbert: A Great Engine of Research. Austin: University of Texas Press, 1980.
- Stegner, Wallace. Beyond the Hundredth Meridian: John Wesley Powell and the Second Opening of the West. Houghton, Mifflin, 1954.
See also 
Historical overviews 
- Age of Discovery
- Notable cartographers of the Age of Exploration
- National Historic Trail
- Americas (terminology)
- European colonization of the Americas
Specific eras, explorers, regions, and efforts 
- Old West + Mountain men
- Amerigo Vespucci, Martin Waldseemüller + Matthias Ringmann: originators of term America