Answer:
to seek better employment and to seek better education.
Explanation:
the 20's and 30's still had many white men acting heavily racist against blacks, especially in the south. they fled north to hopefully find better opportunities
A special one-year tax to help pay for building new schools would serve as an example of how local taxes support the economy. Public school funding is usually based on local taxes and therefore, this example is most likely exemplary of this.
They were heavily taxed. They were prevented from expanding by Britain's refusal to give them loans.
Testimonials, illustrations and explanations are all supporting materials. So the answer is all of the above.