Use Of US Internal Revenue Stamp By Bank In Confederate State

I found this check bearing a Scott #R5 US Internal Revenue bank check stamp. Interestingly, the check was written from an account with a New Orleans bank in December 1864, during the Civil War.

I found it odd that a bank in a Confederate state would be paying a tax to the US government during the Civil War, particularly since the purpose of the revenue stamps was to raise funds to help defray the costs of the conflict incurred by the states of the North.

Does anyone have insight into why this might be and whether such a usage is common?

New Orleans was captured almost immediately at the start of the war, April of 1862.

Thanks.