The continent's first inhabitants walked into North America across what is now the Bering Strait from Asia. For the next 20,000 years these pioneering settlers were essentially left alone to develop distinct and dynamic cultures. In the modern US, their descendants include the Pueblo people in what is now New Mexico; Apache in Texas; Navajo in Arizona, Colorado and Utah; Hopi in Arizona; Crow in Montana; Cherokee in North Carolina; and Mohawk and Iroquois in New York State.

　　The Norwegian explorer Leif Eriksson was the first European to reach North America, some 500 years before a disoriented Columbus accidentally discovered 'Indians' in Hispaniola （now the Dominican Republic and Haiti） in 1492. By the mid-1550s, much of the Americas had been poked and prodded by a parade of explorers from Spain, Portugal, England and France.

　　The first colonies attracted immigrants looking to get rich quickly and return home, but they were soon followed by migrants whose primary goal was to colonize. The Spanish founded the first permanent European settlement in St Augustine, Florida, in 1565; the French moved in on Maine in 1602, and Jamestown, Virginia, became the first British settlement in 1607. The first Africans arrived as 'indentured laborers' with the Brits a year prior to English Puritan pilgrims' escape of religious persecution. The pilgrims founded a colony at Plymouth Rock, Massachusetts, in 1620 and signed the famous Mayflower Compact - a declaration of self-government that would later be echoed in the Declaration of Independence and the US Constitution. British attempts to assert authority in its 13 North American colonies led to the French and Indian War （1757-63）. The British were victorious but were left with a nasty war debt, which they tried to recoup by imposing new taxes. The rallying cry 'no taxation without representation' united the colonies, who ceremoniously dumped caffeinated cargo overboard during the Boston Tea Party. Besieged British general Cornwallis surrendered to American commander George Washington five years later at Yorktown, Virginia, in 1781. In the 19th century, America's mantra was 'Manifest Destiny.' A combination of land purchases, diplomacy and outright wars of conquest had by 1850 given the US roughly its present shape. In 1803, Napoleon dumped the entire Great Plains for a pittance, and Spain chipped in with Florida in 1819. The Battle of the Alamo during the 1835 Texan Revolution paved the way for Texan independence from Mexico, and the war with Mexico （1846-48） secured most of the southwest, including California.