The correct answer to this open question is the following.
How did the residents of the Louisiana Territory respond to those requirements? ( The United States Congress and the President required the citizens of the Louisiana Territory to become a citizen of the U.S.)
The residents of the Louisiana territory were few white American settlers and many Native American Indian tribes. Let's have in mind that the Louisiana territory in those years of the purchase was an immense portion of land. It included 15 modern US states such as Louisiana, Arkansas, Oklahoma, Iowa, Nebraska, Kansas, Missouri, and some parts of other states.
So white residents that had been settled there had no difficult issue to become residents. However, Native American Indians did oppose to the idea of losing their own Indian identity.