11a, 1863 10c Milky blue, well-margined single tied by bold straightline "Jackson" (Mississippi) on cover to Mechanicsville, South Carolina, docketed "March 12th 1863" at left, slightly reduced at either side, very fine strike and cover, the Jackson straightline was the subject of an article by Conrad A. Bush in 1994 ("Confederate Straightline Cancels Part 2: Jackson, Mississippi", Confederate Philatelist Vol. 39 No. 2), 2022 Philatelic Foundation certificate Provenance: Marc Haas (Private transaction)