I'm trying to update an old family tree page (http://www.familytreemaker.com/users/m/c/a/Duke-K-Mcadow/index.html) but this may end-up as a duplicate. It's a summary of some of my McAdow family genealogy. If you've arrived here via an old link for information about my Hawaiian genealogy, that information is no longer posted publicly, my apologies for any confusion.
The earliest McAdow ancestor I have been able to positively identify is my great-great-great-grandfather, George McAdow. He was born in Pennsylvania in 1841, and died in Ohio in 1917. He lived most of his life in Union County, Ohio. I haven't been able to say beyond a shadow of a doubt who his parents were, unfortunately, so I'm stuck there.
But based on tax, census and vital records, the first McAdow families emigrated to the American colonies in the early- to mid-1700s and settled in Pennsylvania and Maryland. They owned a farm or plantation in Harford County, Maryland. In Pennsylvania, a log cabin built in the 1700s by McAdow family members is still standing (search online for the "McAdow-McAdams-Wilson Log House"). They fought on the American side in the Revolutionary War and the War of 1812. It is possible that some McAdows settled in North Carolina in the mid- to late-1700s, too.
In the early 1800s, the McAdow families migrated in two major branches: one to Missouri and one to Ohio. (I'm descended from the Ohio branch.) Many McAdow families continue to live in Ohio today (my father was born and raised in Ohio).
Shortly after settling in Missouri, the McAdow families there began spreading-out to most of the Western and Mid-Western states. The last common ancestor between the two branches of McAdow families died in 1801.