Answer:
Prior to the Civil War the economies of the North and the South developed differently in the early 1800s. Although both economies were mostly agricultural, the North began to develop more industry and commerce. ... The growth of industry in the North helped lead to the rapid growth of Northern cities.
The beginning of 1917 was a very turbulent period during the follow of events of the WWI. Germany announced in January, it would engage against any Allied shipping using its submarine force. In February of that same year the president Wilson told the Congress that the US had broken diplomatic relations with the German government.
In march of that year Germany sank five US vessels, contributing to the already unstable American society. The british propaganda in the US and the deep economical involvement with the Allies carried the country to finally enter the War.
