Well, civil records did not begin in the UK until 1837, if memory serves me, so it will be even harder to find him if he was born in 1808. Before 1837, there were only parish records, and those were only kept by the Church of England, so if he was Jewish or Catholic, it will be even harder still to trace him.
If at all possible, dig around in the US to find out more detail about where in England he was born. Try the Mormons. They keep great records!