The Nicotiana tabacum plant is native to the Andean highland area and spread throughout the continent reaching the Caribbean between 2,500 and 3,000 years before Christ.
The original Pyramid Scheme.With evidence of tobacco use in North America dating back 12,000 years, perhaps the Clovis culture traded across the land bridge and beyond.
Check out "Nova : First Face of America" on Netflix.I don't know if the human population existed or was large enough to migrate on the land bridges. We are comparatively little critters subject to predation and were pretty sparse in numbers, so we may not have had the range to take the tobacco with us. But it is an interesting speculation. I will say, we do miserably underestimate our ancient ancestors. Go back and read the ancients; given their knowledge base, they sound considerably smarter than we do. We've learned so much, and forgotten so much.
The "new" line of thinking is that the ORIGINAL Native Americans (oldest DNA) originally were from the Pacific Islands and migrated up through South America (Peru), not over the Land Bridge. This is all coming out from Genetic mapping.Check out "Nova : First Face of America" on Netflix.