Wash-City Jun 23, perfect strike of cds with manuscript "20" rating on 1799 folded letter to Boston Mass., Extremely Fine and choice, a very early use of the first standardized cds postmark. Estimate  $200 - 300. In 1799, the U.S. Post Office Department supplied twelve post offices with standardized 26mm diameter postmarks. The offices that received them were Washington and Georgetown D.C.; Alexandria, Fredericksburg, and Petersburg Va.; Augusta Ga.; Newark and Trenton N.J.; Newport and Providence R.I.; Pittsburgh, Pa.; and Newburyport Ms. $0 (Image)