Mostly due to the ideas of Manifest Destiny. They started going westwards with the desire to span the United States from coast to coast, and then they started going worldwide. The idea behind it is that the United States were destined to help the world become free and democratic like they were so they started helping people worldwide in rebellions against colonialism or in similar affairs.
<span>The American industrial revolution had a major impact on Americans socially and economically.</span>
Cambodia and Lao--these neighboring countries were the path for the North Vietnamese to reach the southern parts of Vietnam more quickly.
Cambodia and Laos would be the located of the HoChi Minh Trail which was the supply line from the North to the South. Many parts of the trail were underground and difficult to get rid of. The US resorted to air strikes of the two countries which was controversial because they were technically neutral areas.
The dating of artifacts is done by a three age system based on the development of tools and technology.
The ancient civilization of the Incas, which was in South America, was taken over by the Spanish conquistador Francisco Pizarro in 1535. The Incan king at the time, Atahualpa (I think I spelled that right), was held prisoner and eventually killed by the Spanish.
Hope this helps! Please let me know if I'm wrong :)
