What was a major historical claim to oregon by the united states

a) the american army established forts along the regions major rivers by 1800
b) zebulon pike explores the willamette valley in 1803
c) american robert gray turning up the regions major river in 1792
d) john jacob astor discs discovered gold on the banks of the columbia river in 1818

The answer is; C) "American Robert Gray turning up the regions major river in 1792."

Option C, American Robert Gray turning up the regions major river in 1792, is the right answer.

Explanation:

For the thousand years, people have inhabited the land of Oregon. There were several Native American tribes when the Europeans arrived in the land. The Chinook, the Paiute, the Cayuse, the Nez Perce etc were some of the major tribes during this time. Though the European explorers were the first to spot the land, they did not set foot on land. However, both Britain and Spain claimed their authority over the land. It was in the year 1792 that Captain Robert Gray, an explorer from America came upon the River Columbia and called the river after the name of his ship.

the 9th amendment

explanation:

the federal constitution of the united mexican states of 1824 was enacted on october 4 of 1824, after the overthrow of the mexican empire of agustin de iturbide. in the new constitution, the republic took the name of of united mexican states. it was replaced by the federal constitution of the united mexican states in 1857.