What do you infer from Sam’s letter to Charley?

The letter was addressed to Charley but mailed to his grandfather in Galesburg, Illinois. It was mailed in 1894 and now appears in his grandfather’s collection. The letter was suddenly found among the first-day covers where it had never been seen earlier. Moreover, the contents of the letter are exactly what Charley thought about Galesburg of 1890s.

Sam's letter to Charley is a mystery that blends together the worlds of reality and fantasy, and thus, needs further exploring. There are two perspectives from which one can look at the letter. At one level, it proves that Sam has reached Galesburg of 1984. However, if we look at a deeper level, we can infer that the letter is just another instance of his hallucination or dreams of escapism. It is possible that while Charley was looking at the old first-cover letter, he was carried away to a different world where the letter was sent to Charley by Sam. The letter reflects Sam’s undeterred urge that forces him to keep looking for the third level.