Washington D.C was the unions capital.
The same as now.
Washington, D.C.
There were growing craft unions during the Civil War for a few reasons. One of these reasons that they needed to have unity.
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during the civil war washington D.c was the capital of the union
Richmond was the capital of the Confederate States of America during the Civil War.
Anaconda Plan
Richmond, Virginia was the capital of the Confederate States of America during the U.S. Civil War.
Arkansas had two capitals during the Civil War. The capital was Little Rock, but during the Civil War, the Confederate government made Hot Springs the capital also.
Finding a good general.
The capital was Richmond.
Union capital was at Washington DC throughout. Confederate capital was originally at Montgomery, Alabama. Then soon afterwards, it was moved to Richmond, Virginia, which it remained until after Appomattox, when it moved briefly to Danville, Virginia.