It boosted the economy drastically and the wealth skyrocketed. It was made possible to transport goods all across the United States which reduced the prices and made goods readily available fore everyone which opened new markets and also made companies stronger. With stronger companies they paid more taxes so the government also experienced prosperity.
The reason why the Mongols withdrew form Asia was because of horrible weather conditions and diseases. If I had to pick, I would pick A.) Diseases because A is more severe then the weather conditions.
They're called whistleblowers
The Yellow and Yangtze Rivers
