very old Milton Bradley game board, Uncle Sam's Mail US map art

Vintage map print game board made on heavy foldable stock, 34 1/2" x 20" when unfolded. This is Uncle Sam's Mail, and shows the mail routes (by land and sea, or by air? we don't know, as this isn't marked or dated).

There's a little chipping to the edges of the map, but both map and board backing look nice overall. This would make a really interesting piece to hang on the wall or display!