This is my best clue from a story posted here at Ancestry.com: "Thomas (b. 1776, d. 1852) was kin to Robert Perry, son of Samuel Perry, Jr. who also settled in Louisiana near present day Perry, LA. ...his cousin Robert build an 1840 ante-bellum home" There is a LOT of information about Robert, the cousin, even pictures! But, alas, no further mention of Thomas.

(ROBERT)
"He was born in Pennsylvania, of Scotish Irish descent. As a boy, he and his family moved to Kentucky. At age 19, he ran away from home and went (in 1806) to Louisiana leaving his family behind in Campbell County, Kentucky."

(ROBERT'S FATHER SAMUEL)
"Samuel Perry Jr., the father of Robert Perry, was born in 1742, and lived most of his life in Westmoreland County, PA. He was 14 when his father was killed by Indians. ...Soon afterward, with his wife Mary McGrew, he moved to Campbell County, KY. As early as June 3, 1785, they owned land on the Ohio River near the mouth of the Little Miami River. His estate was settled in the fall of 1796. He bequeathed 1,000 acres to his children, located opposite the mouth of the Little Miami. In 1816 they divided it up. Robert, already in Louisiana, assigned his brother David to represent him in his share of the land. He finally sold it in 1848 and 1849."

----------------------------

I know Thomas was NOT the son of John, as so many family histories here have claimed because THAT John, son of Samuel b. 1710 in Ireland, never lived in Louisiana, was not married to Penelope, and only married Violette Moore, by whom he is buried in Missouri (per a post here by a descendent of John and Violette).

SO, Thomas was cousin to Robert. His father was not John or Samuel. Oliver died as a child. David was born the year Thomas William died. That leaves these men:

~William Perry 1745 – 1793
(WILLIAM)
Per Ancestry family trees, William does NOT seem to have any sons born in 1776 or bearing the name Thomas William.
But did he ever live in Louisiana?

~James Perry 1746 – 1822
(JAMES)
"His wife was the cousin to Violette Moore, the wife of John Perry. After a shipping disaster in Baton Rouge, LA. he moved to Elizabeth Town, PA." Ancestry.com family histories show TWO wives. Hannah Irwin seems legitimate. But was she the cousin? And even though there are children born near the time I'm looking for, no Thomas or William or even a boy is listed...

Did THEY have a son born in 1776 Louisiana?