James Armstrong, Cavan

[gh53821]

Hi,
out of the blue it appears my ancestors came from Cavan, moved to Lancashire around 1850 at a guess, as I have no trace of them before that.
All I have on them is:
James Armstrong 1808 Cavan, married Bridget ? 1812 Cavan.
These dates were taken from a later census so can only be estimates.
They moved to the UK and in 1853 had Thomas Armstrong in Staleybridge Lancashire.
Any help would be greatly appreciated,
Kind regards,
Graham