The louisiana purchase which doubled the size of the united states is an example of
a. physical boundary shift
b. small boundary change
c. growing stateless nation
d. drastic boundary change

the historians cited in the article all agree with one another about the cause of the civil war. despite coming from different backgrounds and cultures, the historians agree that slavery was the root cause of the civil war. the fact that all these historiansgenerally agree with one another makes their shared viewpoints more reliable and valid, especially because the historians have different backgrounds and all work for the well-respected institutions of howard university, clemson university, and the university of colorado.

answer; /// i believe the correct answer is (when one group has an extremely high score at pretest;