What war was based on industrial weaponry and transportation systems?

Was the us justified in using the atomic bomb on hiroshima and nagasaki? why or why not?

Which landmark supreme court case ruled that segregation by race in public education was unconstitutional? a.miranda v. arizona b.plessy v. ferguson c.brown v. board of education of topeka d.alexander v. holmes county board of education

What is the name for the main idea behind the settling of western lands by americans in the early-1800s?