My apology for not making clear the possibility of its being a constructed language.

BB has a grammar, phonology, vocabulary, and everything required to be a functional language. I could go into loads of detail, but I won't.

By "not quite done," I mean I am writing stuff in the language to look for kinks and correct them, a process which I have not yet finished.
Example, 1st class masc. noun suffixes:
sg. pl.
Nom. -ys -ap
Gen. -y -ap
Dat. -o -op
Acc. -ym -yp
Loc. -a -ap
By a priori, I mean I'm basing this off of a particular group of languages, thinking of it as a distant cousin of theirs.

Sentence by sentence translation of the remarkably un-nuanced account of the civil war:

Go pohea, ye Aberyhy.
There was a nation of Americans (Was people, she Americans)

Hlutap hahaba subyp, yt hlutap do [hahaba subyp]. [that should be just "...yt hlutap do."]
Some had slaves, but some did not. (some had slaves, and some not [had slaves])

Zuyhatha bibap alyp.
They hated each other. (hated each the other group)

Torohyap Aberyhy, yr hahaba subyp, hlédedyza, rusen Aberyho.
The southern Americans, who were the slave holders, wanted to leave America. (southern Americans, they had slaves, wanted to leave America)

Zutsuhya sohyap u.
The northern Americans did not like that. (Dislike northerns it)

Do hlédedyza.
They did not want it (not wanted).

Hod bahaa bibap alyp. [bibap should be bybap]
So, a war started. (because of that, warred each on the others)

Arz abyap to bahaa.
The war lasted four years. (four years along warred)

Azdam sohyap hahaba trusym.
In the end, the northerners won. (At end, northerns had victory)

Baedam eda lo pohea.
After the war, the country remained intact. (At/from warring one was nation)

Azdym.
The End. (End) [Azdam and azdym are variants of the same word]