Rare Early War Postal Cover From Tennessee to Alabama

A Knoxville, TN CDS dated April 23, 1861 ties a 3¢ U. S. stamp to a cover addressed to Pine Level, Alabama, C. S. A.. A late usage of United States postage into the Confederacy from a Southern state that would not secede until June 8, 1861.

20th century pencil notations on back, else very good condition.