A letter, dated July 10th 1863, from Major General George Stoneman praising Thaddeus Lowe's achievements in balloon reconnaissance during the Civil War. The letter reads: 

Washington DC
July 10th 1863

My dear Sir

Before we part I beg leave to testify to you in writing as I often have in words, my appreciation of the valuable services you have rendered the Govt during your connection with the Army of the Potomac in the use of your "portable Balloons" in the various operation of that Army.

I have been up in them often and never made an ascent without coming down much better informed in regard to everything in my vicinity than I could possibly have been by any other means...

I trust you will not be discouraged but will persevere in your laudable endeavours to serve the Govt and the cause, feeling assured that in the end you will be able to do away with the prejudices with which you have had to contend, and prove to the world the great utility of Balloons and Balloon Signals in the conduct of a war, and remain

Very truly yours
George Stoneman
Maj Genl
Comdg Cavly Corps