It's always very difficult to prove that someone baptised in England is the same person who emigrated to the USA in the early days. Bear in mind that the IGI is also far from complete so there's every chance that your James baptism isn't on it at all. And also remember that some parish registers have been lost. But it's the nearest we have to a national baptism index for that era.
Im hoping the fact that he was well documented once in the US will reveal a similar trend in the UK.
Are there no records in the US which might give a clue as to where in England he was from? If not it's pure guesswork. Do you have the passenger list of the ship he emigrated on? Perhaps other passengers were from the same parish as James.
My closest indication is the fact that my James appeared to have owned land with a Luke Billington; my feeling is that they, or the families, might have known each other in England. Ive copied excerpts from that deed as well as a
possible record for both James and Luke Billington.
My James married Ann Duncombe, who I believe was from Bedfordshire, this also might be a possible link.
"18 Nov. 1663
LUKE BILLINGTON & JAMES TUNE, 386 A. 2 R. & 20 P. "to which since added 270 acs. (in the county of Rappahanocke at the head of Farnham Creek) lieing between this and land of Ro. Bedwell, the bounds of which joyntly are: beg. at cor. tree of Robt. Bayly and on the land of John Williams, running S. &c. neere branches of Totoskey Cr. &c. 18 Nov. 1663, p. 345, (357). Trans. of 14 pers: Jno Searle, Wm. Partin, Jno Young, Fra. Clay, Wm. Wroth, Mary Shell, JNO. TUNE, Cornelious Young, JAMES SHORT, Tho. Ceely, Jno Mount, Mary Hartwell,
Sam.Cornix, Jane Fisher
Cavaliers and Pioneers, Patent Book 5, Page 506 by Nell Nugent"
POSSIBLE RECORD FOR MY JAMES:
James Townes baptised 17 Apr 1620 BLETCHLEY, BUCKINGHAM, ENGLAND
father - William Townes
LUKE BILLINGTON
Luke Billington bapt 5 Nov 1612 BLETCHLEY, BUCKINGHAM, ENGLAND
father - Thomas Billington
Even if you find a baptism that could fit it's still a monumental task to prove it's the right James. First you need to show that he might be the right one by checking marriages and burials in that parish to see if he stayed in England. Did the fathers of any possible James leave a will naming his son James in America? Have you checked the TNA catalogue at http://www.nationalarchives.gov.uk/a2a/ ?
Aye, Ive trawled through that nationalarchives site, which I have to say is quite amazing and comprehensive! Ive looked for every instance of Tune/Toone, etc that I could find and made a digital copy for my comparative records. Ive even plotted where those records came from on a google map to see if some kind of pattern emerged from the dispersal - which was kind of revealing actually.
Secondly, our family line has been pretty consistent with its naming patterns. That is to say, my James named his first son James, which might mean his father was also a James? I do have a copy of my James' will, nothing is mentioned of England in there, the only reference I have is of a John King, who is the person who transported my James over from England. I am currently also searching to find the name of the ship and its departure point - a difficult task from what I am finding out.
Whew!