I purchased the subject RPPC (Real Photo Postcard) addressed to Mr. & Mrs. G. Knapp, Pendleton, MO, on which the sender, named Grace, presumably the girl depicted in the photo, wrote:
Oh! only 24 more days. We will be at you house then
May 25, 1910.
Dear Grandma & Grandpa-
Mother and I are going out this evening for a walk. Papa went away last night to be gone about a week.
The postcard was postmarked 26 May 1910 in St. Louis, MO.
Contact me for free scans.
Paul A. Peterson