To what extent did the territories both help and hurt the United States?

The acquisition of new territories helped the United States through increased economic expansion but hurt the country by dividing it. Increased trade between the east and west occurred as a result of the expansion, and to facilitate this trade new modes of transportation were introduced. Along with this, struggling immigrants came to the United States in hopes of receiving a share of the new land. These immigrants couldn't achieve their dream instantly and often took jobs in factories for low wages, thus benefiting the economy. Despite this economic success, expansion arose issues of slavery and how much power the federal government could hold and caused a divide within the nation. Southern states did not believe in the federal government intervening in state affairs and sought for slavery in the western territories. Both of these issues were only dealt with sparingly and most times left the country more divided. Despite the economic wealth western expansion brought the country, it created a divide that would ultimately lead to the Civil War.