Wow, thanks for the info! The 1860 census info helps. For some reason, even directly searching under the alternate spelling, this info doesn't come up on ancestry. I've never used heritage quest; I'll be checking it out.
I'm pretty sure I have come across your William Meldrum in my searches. Was he a civil war soldier? I know of one contemporary William Meldrum who was; he was with a Missouri Regiment.
And yes, I have been all over the Meldrum boards. Thanks for the suggestion though.