>If you are looking for one canonical, authoritative source to declare something absolutely for you, you will never find it
Even if we treat your source as canonical and authoritative, , it doesn't answer the question I was asking. It only answers a slightly different question of "what was the first instance of a paid advertisement in an American newspaper?", which obviously is going to be American.
>But did you know that the first time a paid advertisement appeared in an American newspaper it happened here in Boston?