[@Sapphira]

If we're going with an actual historical direction and not a comparable fiction, then I guess I can have some fun too:

You are a former Chartrist from the West Midlands who owing to political pressures from the government between 1840 and sometime after 1850 have pulled up stakes and left the Black Country for the United States, landing in the East Coast. There you lead a workingman's life. Marry, have a family, and vibe. But at the outbreak of war you are not able to escape the eventual draft and are inevitably picked up by Union Recruiters as a conscript and sent to war where you serve in the Army of the Potomac. Enter some begrudging loathing of the Irish because Anglican-Catholic disputes but you serve valiantly through the war and retire a decorated war hero.

However, because of the retreat of the Southern gentry class from American politics because of the war, and with the west being opened up, you can take your family west, and you strike out to homestead being fed up with the impoverished living of a factory laborer and seeking your own free land in the vast trans-Mississippian interior.

To add more spice: a veteran of the Crimean War and arriving and living in New York City are eventually join the New York British Volunteers, eventually absorbed by the 36th New York. You serve the full two year enlistment, going home just before Gettysburg but not without first bloodying your already colorful reputation by repressing the New York draft riot and eventually retiring westward out of shame.