Re: Looking for Johannis Jansen / NY -descendents
First let me say that Jansen is a very common name, and as such, difficult to track.Any early Dutchman(and there were a lot) named Jan could have left Jansen descent.Jan Matthyssen was the start of the Ulster County Jansen family, but even then, there were Jansens in Ulster that weren't related.Same applies to the anglicized "Johnson" that developed from the Jansen name.Closest I have in my records of a Hendrick b. 1768, was Henry, s.o. Thomas Jansen, b. Shawangunk, May 3, 1767.I don't have any other info on this Henry, so I can't say whether there is a connection, or not.I have found no positive connections between the Ulster Jansens and Jansens living in other counties, other than Dutchess.
A couple of things puzzle me about what you sent.First, a John b. in 1754 would not be the father of a Hendrick b. in 1768.Next, it is highly unlikely that a Hendrick b. in 1768 would have served in the Revolution, since he would have only been 15 at the end of the war.Since there were a large number of Hendrick Jansens and Johannis Jansens running around, I suspect that records have been mingled here.For Example: I show the following births for different Johannis Jansens: 1741, 1753, and 2 in 1764.Hendrick: 1720, 1731, 1767, and 1777...and this is just from the Ulster County Jansens.Nearly every county had a Jansen family.Hopefully this will help some.Jansen research is quite a challenge, due to the fact that there were so many unrelated Jansen families.