Because of the simple fact that they were the closest places to Europe.
The most reasonable answer is because Native Americans lived there long before Christopher, so he really wasn't the first.
Against all odds the union won. They were outnumbered by confederate soldiers but that did not stop them.
Answer:
expansion of slavery
Explanation:
I know this because of how it was technically not the fate of native Americans in the west and probably not the acquisition of Oregon and all it is left is the annexation of texas and the expansion of slavery so I dug a little deeper and figured out that the annexation of texas happened to happen in 1845 so all that is left is an expansion of slavery which happened in 1840 and was a hugely critical issue facing political parties.
