A few questions:
How does one go from the Canary Islands to the New World, and end up in the middle of the Pacific? At least with the drug plane, could try and argue that they went East, and maybe made a stop or two in Asia. A sailing ship would have more problems with that, and going from the Canary Islands (NW tip of Africa, just south of Gibraltar) to Hawaii (give or take) would be a LONG haul.
Speaking of which, the date they used was 1867. Why was it being called the New World still? Had been known for almost 400 years at that point. Hell, it had been America for almost 100 years. If they weren't calling it America over in Europe, they'd certainly at least be calling it the Colonies, right?
While we're on the date, where were they going with slaves? Pretty sure America had just finished deciding on that one once and for all, and came back with a NO. They wanted him to speak English, so Central or South America aren't likely destinations, either. If they went around South America and tried for the West coast, no slaves in California (or a whole lot else, although it's getting going), and any further south towards Mexico and speaking Spanish would be more useful than English.