Locating Relatives of James Sanders

According to family accounts and his obituary, my Great-Grandfather, James Sanders, was born in Dublin on 4 November 1831.  According to these same sources, he arrived in New York at the age of six.  According to verbal accounts obtained by my uncle from James Sanders (his Grandfather) and other relatives, James, his parents and siblings settled in upstate New York.  Apparently his parents and at least some of his siblings died while James was still a child.  He was adopted by a neighbor. 

I have no actual records, other than his obituary, to support any of this.  The first actual record I can tie directly to my Great-Grandfather is a Minnesota Regiment roster during the Civil War which shows he was a member of the regiment in 1862.  His age on that roster was 31.

My research to date leads me to believe he may have been the James Sanders who arrived in New York from Liverpool on the Adirondack on 27 Jun 1842.  The James Sanders on that ship roster shows James as a child of six.  If this is my Great-Grandfather, then he would have actually been born in 1835 or 1836 rather than in 1831.  The additional Sanders family members listed on the ship's roster were:  James (father), Margret (mother), Janet (born 1831), Andrew (born: 1832), John (born: 1834), and David (born: 1841).

It is also possible that James Sanders arrived in New York on the Catherine Jackson from Liverpool on 4 May 1840.  The James Sanders on that ship roster was 8 years old.  In the 1900 US Census, my Great-Grandfather does say that he migrated to America from Ireland in 1840.

Any additional leads that anyone can provide would be greatly appreciated.

Thanks,

Bill Arnold