What if the Romans had discovered America and colonized some of it?

What if pigs could fly?

We'd need some really heavy-duty umbrellas . . .

By the way, there is a bay on the coastline of Brazil, near Rio, which is known as the "Bay of Jars," because pottery jars were discovered there in the 1970s. An expert from an American university has tentatively identified them as Roman amphorae dating from about the the third century CE. The Brazilian navy no longer allows people to dive in the Bay of Jars. The gentleman who first identified those jars as Roman artifacts, a Mr. Marx, says that the Brazilians don't want people to stir up trouble about their history, and want to keep the story that Brazil was "discovered" by Cabral in 1500.

Apparently, the Romans were not moved to take any action even after they had "discovered" America.