Charles Hook was in Columbia, the charming city overlooking the Susquehanna River in south-central Pennsylvania.
https://en.wikipedia.org/wiki/Columbia,_Pennsylvania
(I am not confident that the surname is “Hook” – the unusual capital letter might indicate “Shook” or some other name.)
In September of 1907, Charles received a postcard from his Aunt Martha.
Aunt Martha mailed the postcard from Carbondale, the city in Lackawanna County of northeast Pennsylvania.
The fortunes of Carbondale rose and fell with the coal-mining industry – the city reached its peak population in 1930.
Carbondale was founded as a coal transport center for the Delaware & Hudson Canal Company, and later became a major depot of the Delaware and Hudson Railroad.
https://en.wikipedia.org/wiki/Carbondale,_Pennsylvania
The face of the postcard is a photograph of the town of Carbondale as seen from the railroad line; the depot is in the lower right.
One sees homes, businesses, and a church, backed up against the railroad tracks.
In the distance, ridges of the Appalachian Mountains form a backdrop to the scene.
The postcard photograph was published by the American News Company of New York – with branches in Leipzig, Berlin, and Dresden.
Printed with the patented “Litho-Chrome process, the postcard was made in one of the German cities.
The postcard has an undivided back, which suggests the print was made a year or two before it was mailed.
Aunt Martha inscribed a brief message in the margin of the face:
“I will send a letter on Wednesday with the surprise”.
It may be that Charles was celebrating a birthday or some other special event for which Aunt Martha was sending a gift.
Charles saved the postcard throughout his life.
One hopes that Aunt Martha wrote the letter and enclosed a “surprise”, and that Charles and his aunt remained postcard correspondents for many years.