New York, New York (possibly)
No Name 

Nickel-silver
ca 1860’s
Length: 34 in; Bell Diameter: 8 in
Wind Instruments – Brasswinds – Saxhorns

Around 1840, Thomas J. Dodworth, Sr., the founder of ‘Dodworth’s New York Cornet Band,’ modified the saxhorns into backward facing instruments nicknamed “back’ard blasters” for use by U.S. military bands that traditionally marched ahead of the infantry and cavalry units. These modified saxhorns called “OTS” (over-the-shoulder) were used extensively during the Civil War.

This is an ‘over the shoulder (OTS) E-flat alto/tenor saxhorn.  It is made from nickel-silver and has three  top-action rotary valves with string linkages.