representation by population;
Knew that the lack of representation by population was going to be an ongoing issue when attempting to settle any dispute whatsoever.
It is valuable to look at these debates to be able to go back and see exactly who was thinking ahead (representation by population) and who wasn't ("Oh no! America is going to invade!")
I should have desired to make my remarks to the House in French,
I think that this is a poor way to start his argument. Off the bat, he is not only alienating himself, but also alienating those around him. Not a good way to make others want to listen to what you have to say.
forced into the American Union
It is important to think about the fear of being "forced into the American Union" in the context of the time. At this time, the American Civil War is still ongoing, and the situation was fragile. Since Canada did not exist and it was only colonies, it is realistic to view America as a threat to the possible development of Canada as a country.
and being, for the most part, of the same blood and lineage
John A MacDonald's racism begins to peer through the blinds with this comment. He does want Canada to be one, and everything he mentions above are incredibly important aspects of Canada, even today. However, in making the statement that Canadians would be of the same blood and lineage, he shows his true colours in his disapproval of minorities and people of colour.
He also highlights an "issue" that other party leaders were also concerned with in the form of the "Alien question" by which the concern lay in the immigration of others (not British) to Canada.
as to the expediency of effecting a union between all the provinces, and the superiority of such a design, if it were only practicable, over the smaller scheme of having a Federal Union between Upper and Lower Canada alone.
He is arguing that the union of all provinces would be better than only the union of Upper and Lower Canada. It is interesting that John A MacDonald knew this before Confederation.
He was likely aware that the system would begin to cause problems between Upper and Lower Canada, which is why he advocated for more seats/say in the form of the other colonies.