What, historically, has spurred america away from political division and toward national unity?

The correct answer is the founding values and principles of the country

America is founded on a strong democratic and idealistic standing. America also has a rich history from which it borrows. This includes the calamity of the Civil War and the lessons learned

a factory opens that mass-produces light bulbs.

explanation:

not sure if that's an answer to your questions but this is an example! : )

answer; sociological imagination;