VERY FINE APPEARANCE. ONLY TEN EXAMPLES OF FLOYD'S GREEN STAMP ARE KNOWN TO US.
John R. Floyd advertised the start of his Penny Post in July 1860. In June 1861, after the outbreak of the Civil War, Floyd sold the firm to Charles W. Mappa, but continued to assist in managing the post for several months before leaving for war in January 1862. Mappa in turn sold out to Kimball & Waterman in May 1862, and the post continued at least until November 1862 and then closed.
The Brown and Blue stamps were the first issued, and the Blue continued to be issued from 1860 through 1862. The Green stamps are known used only in October and November 1862, thus they appear to be the last printing, probably by Kimball & Waterman before the post was closed. The Blue is the most common, and the Brown is extremely scarce. The Green is by far the rarest, with only two recorded covers, five or six used stamps off cover, and three unused stamps (two with original gum) known to us. (Sources: Abt's American Philatelist series on Chicago local posts and Stimmell's article in The Penny Post, Jan. 1997).
Listed but unpriced in Scott. A used example with tiny flaw realized $2,100 hammer in our 2000 Rarities sale.