There is a discrepancy between the 1851 and 1861 censuses in that James mother is listed as Mary in 1851 and then Grace in 1861. It is assumed that the name Mary is an error? The 1851 census indicates that James was 5 months old at that time so that would mean his birth was in 1850. By 1861 James was working in the mines as a tin dresser. James is not listed again in following censuses for Cornwall. He has either died (Possibly death entry in 1863 – death index lists James Hicks 1863 Oct-Dec 5c p.227 Penzance) or has moved elsewhere.

Below is the possibility of James having moved to the US state of Massachusetts in 1870. The dates in the 1900 US Census indicate that this James married Mary Ann Abraham ? The US census places James birthday as Nov 1850. This ties in with the 1851 English census which gave James age as 5 months. As that census was taken in March of 1851 then the birth of Nov 1850 would line up well. Also the year of migration to the US of 1870 would explain why James is not mention in the English censuses after 1861. The US census indicates that James married Mary Ann 30 years before that census. That would mean they married in the year of migration. So did they marry in England or the USA? The US census reveals that James could read and write. Was a cobbler who owned his home. Mary Ann had 13 children of whom only 3 were living at the time of the 1900 US census.

There is a US find a grave entry for a James Hicks at http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRid=159957492&ref=acom

English Marriage Index : James Hicks married Mary Ann Abrahams Jan-Mar 1870 Devon 5b page 444
East Stonehouse St George