This particular event he is referring to is that of Baltimore, when according to him there was a prosperity after the event and that made him believe in these types of events and situations in particulars that may be real.
"Going to live at Baltimore laid the foundation and opened the gateway to all my subsequent prosperity. I have regarded it as the first plain manifestation of that kind providence which has ever since attended me and marked my life with so many favors.....I was chosen from among them all, and was the first, last, and only choice."
