[PeaRidge]

"I'm looking for the reason why tariff revenues more than doubled between 1861 and 1863"

Revenue did not double. Tariff revenue dropped substantially.

[DoodleDawg]

Revenue did not double. Tariff revenue dropped substantially.

In his December 1864 state of the union message to Congress Lincoln put tariff revenue for the prior fiscal year at over $102 million. That's double for 1860-1861.