Chicago to St. Louis, April 15, 1926. Air Mail envelope, signed by Lindbergh on front, for the inaugural air mail flight from Chicago to St. Louis; co-signed by Postmaster William H. Conkling; including a doodle of a U.S. Mail plane at top in an unknown hand. Mounting residue on verso; opened. 4 1/16 x 9 1/2 in. (103 x 241 mm).

An early Lindbergh envelope signed while he was still an air mail carrier, a little over a year before his historic transatlantic flight aboard the Spirit of St. Louis.