What lead to the growth of Detroit? *

The expansion of the auto industry nearly a century ago fueled a growth spurt that made Detroit the fourth largest city in the country. By 1950, the population peaked at almost 1.85 million as people moved to Detroit to work at the Big Three auto companies: Ford, General Motors and Chrysler.

The expansion of copper

becasue in the south they disallowed slavery but in the north slavery was illegial this boilled into because mexico wanted slavery

the answer would be:

b. race