This is an unusual usage of E15a special delivery with C26 on a post card. The postmark is Washington, DC Mar 26, 1944 with "Air Mail", "Special Delivery" and "FEE CLAIMED BY OFFICE OF FIRST ADDRESS" auxiliary markings. Receiving stamp Canon City, CO Mar 29, 1944.
C26 first day of issue was Mar 21, 1944 but the first day of 8 cent rate was Mar 26, 1944.
Unfortunately, it is bent and dog eared but I guess it is still a keeper.

