EXTREMELY FINE. THE EARLIEST RECORDED DATE FOR ANY OF THE U.S.P.O. PHILADELPHIA CARRIER STAMPS AND ONE OF FIVE REPORTED COVERS WITH THE "LS" STAMP.
A few covers and pieces dated in late March and early April are found with the 1849-50 carrier stamps, but most do not have evidence of the year and cannot be reliably dated. This March 13 postmark on a clearly-dated 1849 letter is the earliest use, even assuming the other March dates without the year indicated are 1849 usages. The Philadelphia carrier service was reorganized in February 1849, and stamps were issued at that time.
Ex Emerson, Knapp and Gibson.