What scientific breakthroughs did African Americans make

The Three-Light Traffic Light, Invented by Garrett Morgan in 1923. With only an elementary school education, black inventor (and son of a slave), Garrett Morgan came up with several significant inventions, including an improved sewing machine and the gas mask.

states

explanation:

as the old saying goes, all politics are local. state and federal governments affect our daily lives in numerous ways. yet, in our federal system, there is supposed to be a balance between federal and state power. as james madison envisioned it in federalist no. 51, “the power surrendered by the people” would be “divided between two distinct governments,” creating a balance of power that would enable the “different governments [to] control each other.”