[Razor]

I would say so..At the time of your Civil war, your population was just under Canada's current population of 35 million (31 million).So, from 1860(ish) to now your population increased ten fold. to add an extra 20-25% isn't out of reach..Even within the next 50 years.I know that birth rates aren't the same and there could be a lot of unforeseen variables hindering that curve, but it's definitely doable.

interesting to note, that Canada's population went from around 3.0 million to 35 million from 1860, or ten fold as well, but unless climate refugees become a real thing, I can't get my head around our population hitting your current population in 170 years. Another ten fold increase is a long shot.