The Revenue Act of 1862 was the first income tax law that was passed with a bracket of 3% tax on annual income of U.S. citizens while those with income above $10,000 had to pay 5% tax.
The National Banking Act created a system of national banks which provided stable currency. It was compulsory for new banks to purchase government bonds, therefore providing financing for the war.
Legal Tender Act of 1862 - paper money was issued to finance the war.