Which area was the last to be settled by Americans?
A. regon
B. California
C. Ohio
D. Oklahoma

I dont know what A. was, so then the next option would be california.

Explanation:

saint clair’s defeat, (november 4, 1791), one of the worst defeats ever suffered by u.s. forces in indian warfare, precipitated by british-indian confrontation with settlers and militia in the northwest territory following the american revolution. despite specific provisions in the treaty of 1783 for the evacuation of its forts on the northwestern border, britain had failed to yield these lucrative fur-trading posts. in hopes of reclaiming lost hunting grounds with british support, a northwest indian confederation was gradually molded between 1785 and 1787, consisting mainly of shawnee, delaware, ottawa, iroquois, ojibwa, miami, and potawatomi. kentucky frontiersmen reacted to this threat by initiating raiding parties on native villages as early as 1788, and indian warfare flared up the following year.

c it says nothing about connecting those 2 seas.