Decks, Patios, Porches and Docks - Repairing rotted porch posts

I have turned posts on my porch and I've cut off the rotten bottoms of three of them which I will replace with short pieces from a vintage beam of the same size that was in the basement. I think it was one of the original support collumns in the basement. I'm wondering if there are any good suggestions out there for making a neat, strong joint. I have them cut off pretty good and square. Should I use glue and countersink/toenail some long screws up into the original post? Any ideas on how to make the joint not show through within a year? I have one post that had the bottom replaced. It's a pretty neat job but the paint wants to crack right there of course, so it is detectable. I would be satisfied with detectable, just wondered if there were any ideas.

Also, is there some common type of wood that would have been used for the porch deck? I'm not sure what it is or what to replace it with. It's tongue and groove, about 3-1/2" wide, 3/4 thick. Feels and looks pretty much like pine but I can't smell anything. Maybe yellow pine? It's not very heavy. The house was built in 1885.

Thanks.

...is there some common type of wood that would have been used for the porch deck? I'm not sure what it is or what to replace it with. It's tongue and groove, about 3-1/2" wide, 3/4 thick. Feels and looks pretty much like pine but I can't smell anything. Maybe yellow pine? It's not very heavy. The house was built in 1885.

Maybe I can shed some light on the material
It seems strange now, but by the late 1800's most of Connecticut was pretty much clear cut
The houses would have been made from whatever was available
...that wasn't used for industry (the hardwoods)
I suspect it's pine
The pine would have been what was left of the old growth trees, very different from what you would have growing today
Alot of the green you see around the state-look closely- none of it is over 50 years old
And when you see those tell-tale stone fences in the woods, it often means it's old farmland only recently become wooded again
I'm in my second 1800's house here, and the old pine sure does look different than what you'd buy at the lumberyard
Both houses also had other woods mixed in
But mostly they were pine

I think you're right Slick, mostly pine. But I think pine was (and is) the material of choice anyway because it's not so dense. Lighter and easier to cut. Also with the tendency to grow straight. I think pine is ideal for structural and I think that the deck probably is some sort of evergreen. The Home Depot guy said probably fir and they do sell that there. It seems a little denser than the 1-by's and the 2-by's. Unfortunately it wasn't the same width as mine so I'm going with pressure treated now.
Incidentally, the turned posts I mentioned gave off a distinct smell of poplar when I cut the ends off. The wood has a tight grain with very even growth. Beautiful clear wood and get this, the 6 x 6 beam was quarter sawn, if that's what you call it. Basically, it didn't include the pith, if that's what you call it. What I mean is, I don't think you could by a 6 x 6 beam today that wasn't out of the middle of the tree. Now there's some old growth lumber for ya.
Thanks for your comments.