How clear is the story of the Irish connections? There seems to be no Irish born Percivals (except one George in VA)in the south in the 1860 or 1850 census. There were some Percivals in MO as early as 1840, but on the 1870 your James claims SC as a birth place, so I was focusing there. Pernhaps Jame's Death Certificate will have some names or clies.

One possibility could be that it was James' Grandfather or great Grandfather who was the irish ancestor -- and the story got a bit confused in the transmission. Whatever the case, the key may lie in discovering who brought the Percivals in to AL; unfortunately a very tough nut to crack!

Most of what I have seen on indentured servants always focuses on the 1600's & 1700s-- putting it a bit far back for the father of your James Percival, born abt 1842, but I certainly claim no authority on Irish indentured servants, and don't know how long the practice continued. the early 1840s was the peak time for Irish "famine immigrants" though, so there would have been plenty of Irish coming in to everywhere on the east coast.

there were more than 200 Wrights in Montcomery county, AL in 1870, Lots of black white and mulatto ones, so need some focus on that line of thinking.