The Union raised money for the war by taxing persons based on how much they made which was called .

The black tariff

Explanation:

The Tariff of 1842, or Black Tariff as it became known, was a protectionist tariff schedule adopted in the United States. It reversed the effects of the Compromise Tariff of 1833, which contained a provision that successively lowered the tariff rates from their level under the Tariff of 1832 over a period of ten years until the majority of dutiable goods were to be taxed at 20%.

i think the answer is b.