The louisiana purchase in 1803 doubled the size of america
Capitalism is basically people who want money like Mr Crabs but communism is like everything belongs to everyone and the government takes more
It was challenging because there wasn't many tools then and not a lot of relying resources. As early New England was developing, some crops would die off from livestock eating it, and lack of knowledge of what they were farming. This was some major things in the development of new England's agriculture.
The Acronym M.A.D. stood for Mutually Assured Destruction.
I got this from Brittinica.com and these are the most important details from it:
'Open Door policy, statement of principles initiated by the United States in 1899 and 1900 for the protection of equal privileges among countries trading with China and in support of Chinese territorial and administrative integrity.The principle that all countries should have equal access to any of the ports open to trade in China. But after Japan’s defeat in World War II (1945) and the communist victory in China’s civil war (1949), which ended all special privileges to foreigners, made the Open Door policy meaningless.
I hope this was helpful.