Which event led to the naval blockade around the southern states

Why is it useful for historians to base certain studies on the analysis of historical themes

In a low-income household in the developed world, more than 30% of a woman's income typically goes toward a. transportation costs b. child care c. clothing and incidentals d. the repayment of educational loans

Of the following, who would be the least affected by the telegraph? eastern industrialists western businessmen city dwellers native americans