Re: Brigham?
Yes, "Brigham" is hardly of recent coinage. The same can be said of Charleston and Cedar, though those two are less commonly seen as given names.
Brigham Young was born in 1801, and presumably named not long after. A quick Google ngrams search didn't turn up an earlier use of "Brigham" as a given name, though of course it's been a surname and place name in English for quite some time.
One site claims "Charleston" has been in use as a given name since the start of the twentieth century, based on US SSA data. It looks like the SSA website doesn't support searching for less-common names via the interactive interface (presumably the other site is using a web API, which I can't be bothered to ferret out), so I haven't confirmed that. In any case, it seems to have picked up in the 1970s, so for the US, at least, it's not novel either.
I couldn't bear the thought of any further investigation into the question.
Biting the hand that feeds IT
