How did the blaine's travel to the oregon territory?

answer:

in 1846 the oregon treaty was signed between the us and britain to settle the boundary dispute. the british gained the land north of the 49th parallel, including the vancouver island and the united states received the territory south of the parallel.

the adams–onís treaty of 1819, also known as the transcontinental treaty, the florida purchase treaty, or the florida treaty, was a treaty between the united states and spain in 1819 that ceded florida to the u.s. and defined the boundary between the u.s. and new spain.

yes there are written records of the first migration of humans to the americas

so thats true