Was the national flag of the Confederacy banned after the Civil War?

Answer 1

It was not banned by Congress, so no, the federal government has not banned it.

California recently passed a partial ban of the Confederate flag; they disallow state agencies from displaying or selling the flag. Otherwise, no state has banned it. In fact, a few Southern states have even incorporated it, or elements of it, into their current state flags. This may be changing, however, in the months to come following the tragedy in Charleston.