Today, an old envelope with a Chattanooga, Ohio, postmark. This envelope is postmarked 22 January 1896 and is the earliest Chattanooga postmark that I have.
It is addressed to:
Germania Publishing Co.
286 & 288 West Water St.
It cost 10 cents to mail this letter in 1896.
Stamped on the reverse is that the letter was received in Milwaukee on 25 January 1896. It was received in three days, which seems like a pretty quick delivery service back in 1896. I’m not so sure things have improved all that much in the last 125 years.
Unfortunately, there is no return address on the envelope and the envelope is empty. I would venture a guess that the envelope contained the payment for a subscription or a subscription renewal.
Also stamped on the front of the envelope is Registered No. 12. Does this mean it was sent registered mail? Maybe, if a check or money was being sent.
I have written about the Chattanooga, Ohio, post office before. After looking at the Appointment of Postmasters records, it appears the Chattanooga Post Office operated from 1882 to 1900 or 1904. Just after the turn of the century the mail was sent to Rockford.
According to the Postmaster records, Philip Deitsch was Chattanooga’s Postmaster in 1896. 
The Chattanooga Post Office was in the frame building that stood just south of where the Chatt Bar is today, located in what was Egger’s Grocery store.
Semon Egger had a mortuary in the upstairs of the same building. Hmmm. A post office and a mortuary in the same building. Good thing they didn’t have mail-in voting back then. But I digress…
The list of appointed postmasters in Chattanooga (1882-1900):
Philip Hill, 18 Sep 1882
John Schlenker, 31 Aug 1885
William Fender, 8 Sep 1888
Jacob Deitsch, 24 Dec 1889
Henry J Cordier, 9 Jul 1891
Frederick Heffner, 15 Jan 1894
Philip Deitsch, 16 Jul 1895
Andrew Leistner, 10 Apr 1899
George R Hagerman, 30 Nov 1891
Mail to Rockford 3 May 1900
Charles F Wagner, 14 Sep 1904 
A nice piece of Chattanooga history.
 Record of Appointment of Postmasters, 1832-1971, National Archives, Roll #100, Chattanooga, Mercer County, Ohio, Vol. 38, (1873-1891), p.316, & Vol. 79 (1891-1930) p.367-368; digital image, Ancestry.com, viewed 12 Nov 2020.