Just out of curiosity I did some research on your behalf.
Alas, no luck.
Interesting his oldest son, Charles, listed in the 1860 census was also b New York age 7.
So Warren was married before he came to Edgar Co., IL for some unknown reason.
And then after that he had a hard time staying in one place.
For whatever it's worth, I volunteer as coordinator of the Alexander DNA project, and if you can find an Alexander male descendant to sponsor, I can gladly advise you.
There are some 270 Alexander men who have tested their DNA.
Will send the lineages if you are interested.