1900, U.S. Postal Station, Paris Exposition, May 19, 1900. Three strikes of duplex postmark (Bomar type P00-01) tying three 5 c green and 10 c black (corner flaw) on cover to Germany with receiving backstamp Wiesbaden 20.5.00 and blue crayon for taxe. Fine and the earliest known usage of this postmark!
