Thornton Abby/ey is not a place but, as mentioned, there is a property with this name in the village of Thornton Curtis, Lincolnshire. There were no people named Parson/s or Thornton living or born there however. There is also no Charles Thornton with a mother Louisa on census or baptisms for the relevant period who was born in Devon.
So, since Charles could spin a yarn, it seems, then I will spin one too which you can keep on the back burner!
What, if anything, could be true on his marriage certificate I wondered? His father is given as W T Thornton - so were there any W T Thornton's in England at the relevant time. Assuming the obvious I looked for William Thomas Thornton of some means (since citing Thornton Abby as a birthplace sounded somewhat grandiose).
On 15/4/1841 at St. Pancras, London a William Thomas Thornton, of full age, 'Gent' married an Elizabeth Evelyn Darvers (think it should be Danvers).
If you 'google' him you'll find quite a lot about him - he was born 1813 in Burnham, Buckinghamshire, was an author, civil servant, etc.
W T and wife had 3 children - first 2 born St. Pancras and youngest in Marylebone. They lived in Marylebone for a while and later moved to Kensington where both he and his wife died.
Now for my 'yarn' - a Charles Parsons (Parson itself being not such a common name and none born in London at relevant time) was b.18/8/1855 and bp.29/9/1855 St. Pancras, son of Louisa Parsons. He was born in the Workhouse. In the words of all good mysteries 'what happened next'?
I can find no trace of this child after his baptism and no idea who Louisa Parsons was (although there were a number of servants with this name in London in 1851. Louisa may have married and Charles appears under her married name on 1861/1871 census but who can say.
Certainly, the prosperous William Thomas Thornton had various servants - was Louisa Parsons one of them 1854/55? Without wishing to malign said gentleman was it possible he had a 'dalliance' with one of the servants i.e. Louisa Parsons who was 'cast off' by the family once her pregnancy evident and who had to resort to the Workhouse once destitute? Did she tell her son exactly who his father was? For some reason I believe his mothers name is real (and Parsons rather than Parson) and since he doesn't appear to have been born a Thornton then illegitimacy seemed the way to go.
All if's, but's and maybe's I know but the scenario itself could be a possibility. Once he reached the US Charles 're-invented' himself, that's for sure!
Annette