Nice try sport but treason does not apply according to this. "Whoever, owing allegiance to the*United States, levies war against them or adheres to their enemies, giving them aid and comfort within the*United States*or elsewhere, is guilty of*treason and shall suffer death, or shall be imprisoned not less than five years and fined under this title but not less than $10,000;
The Confederacy withdrew from the Union and fought the Union as a separate nation. Therefore they had no allegiance to the Union.