The British tried to keep settlers off of the Indian Lands. They respected the land west of the Appalacians as the Native Americans land. After the Treaty of Paris the Revolutionary War ended between the USA and Britain the west was opened up. Great Britain abandoned the claims to the trans-Appalachian region. The Native American nations were left to take "care" of their neighbors.
This data is called "secondary data".
An example for a usage of a secondary data is when a researcher takes up a data collected by someone else, for exam ple a large survey, and analyses this data to receive new insights from it - this is a fairly common practice. Often for example official government data is used by scientists
