To explain the "no west" comment, in 1812 the American "west" only reached as far as the Mississippi River.
The northern states were heavily involved in international trade, having the ports and ship building yards. The men who sailed on those ships were likewise mostly from the north and were the ones being impressed into the British navy. The agrarian south's interests lay entirely in the production of tobacco, cotton, sugar, sorghum and a few other large cash crops. The commerce was mostly within America and they had little interest in shipping issues.
All the illnesses that are being passed done generations. Like cancer from all the chemicals and radiation. Or the PTSD that is passed down with the generations. There are a lot of illnesses that can be talked about.
Marco Polo traveled during the middle ages (AP period 3), for this the communication technology was not very advanced and Western Europe didn't really know the situation of East Asia and vice versa. When Marco Polo explained his travels to the Europeans of the greatness of China many Europeans decided to go and see for themselves if this greatness was indeed true. When the Europeans arrived in China they were very impressed and a new promotion of travel to China emerged, INCREASING China's economy.
The Battle of the Argonne Forest was a World War I military engagement, fought between the American Expeditionary Force and the German Imperial Army, from September 26 to November 11, 1918, in the forest of Argonne, on the Meuse River, northeastern France.
Answer: the American expeditionary force
I think none of the above would be your answer.
