The shoulder patch would indicate this individual was a member of the 119th Aero Squadron, a World War I unit of the US Army Signal Corps Aviation Section dedicated to aerial reconnaissance. The wiki entry lists the following points of this units history:
- Organized as 5th Aviation School Squadron
- Re-designated 119th Aero Squadron, September 1917
- Re-designated: 11th Detachment, Air Service Aircraft Production, August 1918
- Langley Field, Virginia
- Demobilized: 29 May 1919
(The 119th has since been designated as a New Jersey National guard unit, the 177th Fighter Wing)
This units formation is also discussed in the book Joint Base Langley-Eustis
By Mark A. Chambers
The chevrons on the soldiers left sleeve indicate time in service, as discussed here, with one chevron awarded for each 6 month period. The rank insignia on the right shoulder below the patch would indicate a sergeant.