I looked for Julian Grabowski in Ancestry trees. He sounds like a different guy. Those trees have him born 29 Oct 1818 in Radcze, Lubelskie, Poland. His father is Francis Ludwig Von Grabowski (1784-1851) and his mother is Anna Christina Pohlmann (1786-1871). I have taken that from a tree that has pictures of Julian Grabowski and Margaret Wiley, so that looks pretty reliable.
I think that means we are back to wondering what happened to Adam in Perry County after the 1 Jun 1850 Census that sent Harriet scurrying back to London, giving birth to Sophia in New York on the way home.
Geoff