Read of the time , the generation before yours. The new fields will have new materials. But the best material of an old, or long lived field, is the stuff before your teachers. Read what your teachers did to understand what they aren’t telling you.

How many presidents held slaves?

http://www.nas.com/~lopresti/ps.htm

A whole lotta cotton to build out a country. But the flag is now made of the finest poly blend.