Ex-Confederates were traitors, that much is true. Were they never pardoned or otherwise acquitted of treason in a court of law then that would still be true today. Of course, that is not what happened: President Andrew Johnson pardoned them all unconditionally, and in the case of General Robert E. Lee (whose pardon was not processed due to clerical errors) his pardon was made effective retroactive to the date of application by an act of Congress.
Ex-Confederates are all therefore excused of their crime of treason, and to still attack them further citing that crime is baseless and unwarranted. They are Americans, and the men who fought are all American heroes who ultimately wished for a united and healed nation.
Calling Civil War era Americans traitors today is ruthlessly divisive rhetoric that only serves to sow conflict in a time when the country really does not need that kind of incendiary bullshit. Everyone who spews this false narrative should be ashamed of themselves, they are throwing mud upon those who chose to pursue peace instead of generational animosity.
[1]: https://constitution.congress.gov/browse/essay/artII-S2-C1-3...