I was thinking the "Star of the West" incident was on the 19th, but it turns out that I misread the publication -- seems like I can't trust my eyes or my memory these days.

Anyway, since the MS militia wasn't actually firing AT the Tyler, this incident doesn't really fit the criteria of "shots fired in anger." However, I thought this was kind of an interesting story, since the Tyler was later to become an active vessel of war, so I copied the headline from the Vicksburg paper.