The ancestors of today's Native Americans arrived in what is now the United States from Asia via Beringia at least 15,000 years ago, and maybe much earlier. Following it, a wide range of individuals, civilizations, and cultures emerged. These included the Clovis people, who dominated most of North America between about 13,000 and 9,500 years ago; the Meskwaki people, who lived along the Mississippi River when Europeans first came to America; and several other tribes.
Scientists believe that some ancient humans may have migrated to Europe because they found conditions there more favorable for survival. One reason might have been that Europe was not as affected by the Ice Age as was North America. Another possibility is that ancient humans may have traveled across land bridges such as the one that connected Europe and Asia during certain periods of time.
For example, DNA evidence shows that early Americans had contact with people from both east and west of the ocean. Also, different cultures developed on each coast - including evidence of sophisticated engineering techniques used by some builders. Finally, new evidence suggests that some ancient people may even have traveled across the Atlantic Ocean.
Paleo-Indians, the progenitors of Native Americans, followed herds of animals from Siberia over Beringia, a land bridge between Asia and North America, into Alaska some 30,000 years ago. These people had expanded over North and South America by 8,000 B.C.E. or more.
The first Americans came from east of the Atlantic Ocean. They were nomadic hunters who traveled across what are now Canada and the United States. Their tools were made out of stone and they used animal skins for clothing. They left no signs of their existence other than occasional rock drawings. These people may have been ancestors of present-day Indians.
The second group to arrive in the Americas was made up of Africans brought as slaves to the Caribbean island of Barbados. They were used as labor on large plantations that produced sugar for sale on European markets. In the 17th century, many of these slaves were transported to North America where they worked on farms and in homes without ever being allowed to go free. This is how Native Americans acquired some of their most important skills - farming, hunting, and fishing - which previously had been done only by immigrants from Europe.
Native Americans built cities with walls and streets when they had enough food to spare. They also developed a writing system based on symbols cut into bone or wood. Some of their inventions include bows and arrows, rafts, and sails.
Native Americans' forefathers parted from the people of Siberia some 25,000 years ago. Later, between 17,000 and 14,000 years ago, they crossed a land bridge between Siberia and Alaska, making their way into the Pacific Northwest. About 12,500 years ago, they arrived in South America.
Some scholars believe that some of the first Asians to reach the New World were native Americans themselves. They would have traveled across the Bering Land Bridge during one of its open periods about 20,000 years ago. Others think that another group of Asians reached South America first, followed by some Native Americans traveling along the coast of North America.
In any case, the first Americans showed no evidence of any direct connection with people today called "Asian." They looked more like Europeans, with dark skin and long black hair.
After arriving in the New World, these original Americans began to mix with other tribes. Some of them stayed in the new countries that they helped form, but many others returned to Europe or Asia. Over time, those two continents became more populated with modern humans.
The terms "Native American" and "Indian" are used interchangeably by most people. This is incorrect because a "native" person is one who was born in a place. People don't become natives later in life when they leave their country; rather, they are immigrants or refugees.
They mostly agree on the larger picture. There they met up with other early inhabitants of the Americas: another wave of immigrants from Asia who were fleeing a more severe climate than what we have today. These people brought with them crops such as wheat and barley.
However, there is some debate about the details of this story. Some scholars believe that Asians came first, then Europeans entered the continent later. Others point out that modern technologies show that Asian populations were moving into North America long before Europeans arrived. Still others argue that evidence for large Asian populations has been misinterpreted or even fabricated by scientists in an effort to prove that Europeans were the first inhabitants of the New World.
In any case, it's clear that humans had been present in North America for many thousands of years before Europeans arrived.
The earliest Americans came at least 16,000 years ago, and they most likely arrived by sea. American Indians may have used boats made of wood or bark but also probably had other technologies available to them. They may have built canoes from scratch or repaired existing canoes when needed. In addition, they may have captured or traded for boats with more advanced technology - such as boats made of metal or wood - that later immigrants would have used.
There is evidence that some Native Americans traveled long distances by water, probably using boats made of wood or bark. For example, the maritime culture of the Na-Dene people who lived in what are now Canada and Alaska was known throughout much of the northern hemisphere. The first Europeans to visit North America saw large wooden boats being used by the natives to travel along the coast; these ships were able-bodied vessels capable of holding many people and goods.
However, it is not certain that all Americans came by water. A great deal depends on how you define "by water". If you include land bridges like the Bering Strait or areas where rivers run into the ocean (like the Columbia River), then sure, most Americans live near water!