I thought his burial place is unknown, though some say his bones are beneath a statue of Washington somewhere.
Nope, In Savannah. They did get DNA enough to confirm this.
The story would pop up every few years in the Savannah paper. Was he buried at sea? On land? Elsewhere? Then they found bones. At one point, they were in a box in the Courthouse, but, they are now under his statue.
A nice little general article here: https://en.wikipedia.org/wiki/Casimir_Pulaski
You’ll want to dig more if you want more scholarly.