The answer is:
The major industrial cities became overcrowded as workers from rural areas moved there.
and
Because of the steady increase in food production, the population nearly doubled between 1800 and 1850.
Railroads had an impact to increase transportation throughout the country. It made it more easier to get to other cities or states depending on which railway you were going.
The Oregon treaty ended the dispute between Great Britain and America of claiming Oregon country to be theirs.
<u>Explanation:</u>
The Oregon treaty is a treaty that was signed between Great Britain and the United States of America. It was signed on the fifteenth of June in the year 1846 in Washington, D.C.
The aim and the purpose of the Oregon treaty is to bring an end to the Oregon boundary dispute where America and Great Britain were claiming Oregon country to be theirs which was jointly occupied by both at one point of time.
