Carroll was very close to George Washington. He was the minister Washington called for last rites. Given that last rites are a Catholic sacrament, that’s a very intriguing action.
You're right that Carroll was friends with Washington, but he was not called for last rites as far as I've ever heard. There is a very old story that circulates about Washington receiving last rites at the hands of a Jesuit priest, but that legend has never been confirmed. More details may be found here:
Did George Washington die a Catholic?
I was thinking Carroll was that Catholic priest. Turns out it was, in fact, Fr. Francis or Leonard Neale. Washington was friends with Carroll, who was Neale’s bishop I’m not sure why Neale was sent instead of Carroll.
The legend is doubted in that link based on Washington’s freemasonism, but as I just posted, that didn’t suggest any antipathy towards Catholicism, but rather a basis for mutual respect.