Briefly, James and Mary McClintock are found in Wheeling, Virginia in the 1850 US census. James is a ship's carpenter, born in Ohio. Just two houses away are John and Hannah McClintock and family. John is also a ship's carpenter, born in Ohio, and just a couple of years older than James. My guess would be that John and James are brothers. They are in Wheeling, where McClintock tradition says James was born; James is a ship's carpenter, as he was in the 1870 census where I first found our James McClintock. The Wheeling James seems to be ours. When John died in Wood county several years later, his death certificate listed his parents as Noble and Ellen McClintock. It is reasonable to assume that John and James were both sons of Noble and Eleanor McClintock.
There are some inconsistencies, though:
1) Family tradition says James was married to Ann Wilkins. There is no mention of a first marriage to a Mary, as in the 1850 census. (However, the ten year gap in ages between the first two children shown in the 1870 census is a good indication that the first child was born to a first marriage, and the others were born to a second marriage.)
2) From census records for Noble and Eleanor, and a daughter Elizabeth, and from the earliest known land record in 1825, I would conclude that Noble and family immigrated from Ireland to the United States in the mid-to-late 1820s. This is inconsistent with James and John census records indicating they were born in Ohio, W. Virginia, and other places, prior to that year. (However, a death record for Elizabeth says she was born on the ocean in 1808, indicating a family immigration in 1808.)
To shore up the addition of Noble and Eleanor and family to our family tree, I am searching for any records supporting two marriages to James McClintock and supporting an earlier immigration of Noble and family to the US. If you know of any such records, please contact me.