This is partially true, as this would have been pre-Steamship. However, by this point, most European nations had access to Clipper ships, which were able to quickly cross the Atlantic before logistics became a serious problem so long as they remembered to stock up beforehand.
It wasn't until the Steamship that Transatlantic Crossings were truly safe or easy, but Clippers were more than able to get the average crew across without Herculean feats of logistical power. If the British weren't also involved, the Ocean's challenges alone wouldn't have stopped South America from being crushed under Europe's boot. Again.
This, however, is right on the money. It also helps that a lot of the regions in question were already unstable and weak thanks to the receding Ottomans.
EDIT: Oh, and 55 is a player Region. I don't think they'll like it very much if you colonize them.