Final answer:
Harmon Gow was a stagecoach driver who had extensive knowledge of the families on his route.
Step-by-step explanation:
The phrase 'Harmon Gow, who had driven the stage' implies that Harmon Gow was a stagecoach driver. In pre-trolley days, before the advent of electric trams, stagecoaches were the main mode of transportation for long-distance travel. By mentioning Harmon Gow's occupation as a stagecoach driver, it suggests that he was knowledgeable about the families and history of the area he travelled through, as it was common for stagecoach drivers to interact with passengers and gain information about the local community.