Hmmmm, a shame no answer has come. Are you still interested?
Couple problems with your query - I don't point them out to be critical, but as part of working toward a solution.
You give no date of birth or date of immigration;You don't have his wife's name or descendants' names. These gaps make it impossible to pick "your" George Hewitt out of the group of men named George Hewitt who could be yours. If you can add his DOB and immigration year, please post them.
Share your sources for the various statements you make: that might help.
Couple statements are contradictory, as you point out. "He was reportedly killed accidentally during the war [American Civil War], due to an accidental death." Yes, accidental death is often fatal! hehe
"He may have also deserted in June 1861 from Fort Snelling." Soldiers stationed at Fort Snelling, Hennepin, Minnesota, in 1861 were there to control the strained situation between white settlers and Native Americans in the area. If he deserted, he really didn't desert from being a soldier in the American Civil War. In 1862 violence broke out in the area, as the native people rebelled against ill treatment and broken promises of the white government. I believe that the year before, ca June 1861, would have been calm, no bloodshed or open fighting, so that person who was a George Hewitt at Fort Snelling in 1861 was likely not deserting a war of any type.
You seem not to know his children or his parents - he is just floating there with no grounding in reality. You know of his existence somehow. Please share that so that volunteers at Genforum have a place to start from.
In sum, please say more.
Again, not trying to criticize your query, but rather help you get to the bottom of your mystery.