Thanks for responding to my post - you're sure right that for every answer there are two more questions.
I'm sure you've seen Little's book on Genealogies of the Passaic Valley, NJ, written in the 1850's. In it, he says Samuel VanSickle was the father of Zach Sr. and Anthony and Christina, and that Zach Jr. married Rosannah Bowman on 20 Oct 1789. He also says that Zach Sr. and his family, excepting daughter Huldah, left NJ for western Pennsylvania.
I can't help but think this accounting is muddled. Zach Sr. and Anthony/Christina are of different generations. I suppose Samuel could have had two wives and two different sets of kids, but a simpler explanation is that Anthony and Christina are the children of Zach Sr. and they went with him to Pennsylvania.
I had thought the VanSickles would have made the trip to Ten Mile Country with the VanMaters in 1769-70 or so, but the exact marriage date given by Little would indicate that Zach Jr. and Rosannah were married in NJ, in which case the VanSickles came to PA in the early 1790s.
Then, within just a few years, Anthony and presumably Zach Sr., along with Henry VanMater Sr. and Absolom, are scouting for land in Mason County WV. And by 1800, Anthony and Rebecca and Henry Jr. and Christina are living in Mason County.
You indicated in an earlier post that Zach and Rosannah had also bought land in Mason Co. and were living there in 1810 according to the census. I've not been able to find them in the 1810 census database on Ancestry.com - wonder why?
To complicate things there is a Zachariah VanSickle in Allegany County, Maryland, in this same exact timeframe who married Mary French and established a whole line of VanSickles in western Maryland. I wonder if Rosannah died and this is Zach Jr. marrying for a second time.
In any event, I'll keep trying to find out more about our Anthony and Christina and let you know if I turn up anything interesting. (I think you and I might be first cousins x7 removed!)