free frank on March 15, 1848 folded letter to Washington, DC, endorsed "on p. office business" and "free", vertical filefolds, otherwise very fine, Postmaster James M. Buchanan's signature will be familiar to anyone who has seen the Baltimore Provisional stamps and stamped envelopes, after eight years as postmaster he became Minister to Denmark and passed away in 1876 at the age of 73, a lovely collateral item