These images are contained within an envelope (labeled as a "letterette"), ready for mailing. Several men are pictured outside a structure with a US flag atop.
E. C. Knopp Co., Milwaukee
Midway Village Museum
74.593.8 7 of 23
3.5" x 5.5"
“Post Office,” Midway Village Museum - Digital Collections, accessed March 27, 2023, https://midwayvillagemuseumdigitalcollections.omeka.net/items/show/831.