Fabric, Insignia, 139th Aero Squadron, United States Army Air Service

This "Mercury" fabric insignia represented the 139th Aero Squadron of the United States Army Air Service during World War I. It was removed from a Spad 13 belonging to the unit.

The 139th Aero Squadron was a day pursuit (fighter) squadron as part of the 2d Pursuit Group, First United States Army. After the 1918 Armistice with Germany the squadron returned to the United States in June 1919 and was demobilized.