It was primarily the "B. Young American" movement that was in favor of U.S. expansion in Latin America, although it should be noted that there were others who were in favor of such expansionism as well.
The Doctrine that eased Cold War tensions was the Nixon doctrine
No, it is false that the Xiongnu became the direct ancestors of the Mongols, who ruled China up to World War I, since these were a nomadic people, and the leadership in China by then was in different hands.
Miller Reese Hutchison tried to make the first hearing aid.
The main reason why there was a massive immigration towards the Sun Belt was because it was unoccupied relatively to the other areas of the US, this meant that new servrices and industries could be developed for the young and flourishing naiton.
