Answer:
C. manufacturing
Step-by-step explanation:
With the Independence of the Thirteen Colonies in 1776, the colonies became independent states, but united in a Federation, with republican and presidential political representation. States in the northern region concentrated on the development of industry and, to that end, needed free and salaried labor to operate the work within the factories. Prior to the secession war, the northern states had 80 percent of manufacturing capacity in the United States. The formation of the working class and the industrial bourgeoisie in the North has also produced a specific way of looking at political activity and civil rights.