If you have lived in a Northern border state or Florida at one time or another Canadian coinage isn't that uncommon of a phenomenon. However, as the title suggests this thread only pertains to Canadian coins found in circulation in the United States. With that out of the way here is the inaugural find for this thread I found today at a South Georiga Firehouse Subs.
Nice find the oldest Canadian cent I've seen in circulation was a 1929 penny I found near Gainesville FL a few years ago.