This white border postcard depicts "Concert Day at Delaware Park," in Buffalo, New York. It's postmarked August 1, 1945. On the reverse, "Bill Ann," (also signed "Billi") writes to Mrs. Margaret IRWIN of Hastings, MI. Unfortunately, some of the writing is obscured and I can only make out "Will... to see you ... -ur way to Calf. Got a good job. Will see you soon."
The only information as to the maker of the card is a tiny logo with the letter "M."