Theodore Judah was the person who convinced the railroad officials that it was possible to build a railroad line across line across the Sierra Nevada Mountains.He is also considered as the "Father of first Transcontinental Railroads.Judah had many opportunities that the people prior to him did not have.
He exclaimed that the employers tricked them and didn't give them almost anything for their work. He provided information on how much he and his fellow men produced, which was a lot, and how they only got enough to eat. They were still being treated as slaves and were not allowed to see their wives or sisters or anything similar by their employers.
An argument for why the Native Americans should have the right to remain on their lands would most likely be based on the fact that they have a historical right to this land and own it even without the standard documentation of ownership. Native American populations inhabited certain regions like the Western Plains for centuries and their removal was arguably unjust and against American values. Therefore, one could also argue that their land should be accorded to them based upon American respect for private property, human dignity, and liberty.
Nicolaus Copernicus was the one who proposed the heliocentric theory.