What laws did the federal government pass to increase funds needed for fighting the civil war?

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.