Final answer:
Northerners financially supported the Union during the Civil War through war bonds, a form of loan to the government. Treasury Secretary Salmon P. Chase and financier Jay Cooke were instrumental in raising funds, also facilitated by the printing of greenbacks under the Legal Tender Act of 1862.
Step-by-step explanation:
During the Civil War, many Northerners supported the Union army by lending money to help pay for the conflict. This money was generally referred to as war bonds. The North relied heavily on loans, taxes, and specifically on these bonds to finance their war effort. Northern citizens were encouraged to buy war bonds as a patriotic act, often in denominations as low as $50, making them accessible to a wide array of the population. With the facilitation of treasury notes and taxes, and the credit from European banks and the American people, the Union financing strategy was crucial to sustaining the campaign. Additionally, Treasury Secretary Salmon P. Chase played an instrumental role by working with financier Jay Cooke to raise the necessary funds through bonds and bank loans. The Legal Tender Act of 1862 also led to the printing of paper money, known as greenbacks, to aid in financing the Union's expenditures.