What line was drawn along the Appalachian Mountains by Britain that prevented the colonies from pushing west into Native American Territory?

in his book, the riddle of the rosetta stone, james giblin talks about how there was a young british polymath and physician named thomas young who made a lot of advances on the deciphering of the rosetta stone. he says that even though young made a lot of mistakes because he was working under false assumptions, he also made huge contributions like deciphering three out of the seven symbols (more than anyone else before him). young published his findings and continued his good work but he wasn't able to progress much further due to some unfavorable situations, he still laid the basis for many other scholars and of course for the man who has been generally known to have deciphered it, jean-françois champollion

can you list the answers so i can answer the question

the correct answer is: the sioux followed the order and remained on the reservation.

after many confrontations between native americans and white american, in 1868, a reservation for the lakota sioux tribe was established in dakota territory, in this reservation they were able to hunt ad to move freely. in 1874, many sioux followed the order, given by the federal government, of remaining on the reservation in which they were already living. the problem arose when, in 1874, gold was found in that area by lieutenant george armstrong custer's military troops, and lieutenant custer insisted that the sioux must give up their reservation land in the black hill of the dakotas.

the united states government opted for moving the sioux to a new reservation. siting bull, leader of the lakota sioux, protested the united states government's demands for the lands where the lieutenant custer's soldiers found the gold. but finally they left the reservation lands and went to a camp along the little bighorn river in 1876.