If you are looking for one canonical, authoritative source to declare something absolutely for you, you will never find it. No such thing exists for any matter. That is a myth of the internet and people raised on it.
>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?
The classified ads section in a newspaper is valuable, and you can discard it. (If you meant ads stuffed around articles: yes, that annoys me, but I'm also not familiar enough with the papers that do that to name one.)