Identify this USAAF biplane
That is a Douglas O-38E, with sliding cockpit windows and rounded tail.
The tail on the right of the picture is also a Douglas O-38, but another version (standard, B,C &amp; F had such tails)

Source: wikimedia Photographer: USAF 
It seems that the picture in the question is damaged; there are some stains covering the area below the horizontal tailplane and also the arms crest on the fuselage. It seems that the arms crest is a circle with a cross in it. This is the insignia of the 33rd division,  Illinois National Guard.
Some of their other O-38's are pictured here
A picture of possibly the same aircraft with the insignia clearly visible can be found on alamy.com