The most significant environmental effect of mining is

Pollution and Land erosion

Explanation:

Mining effects the water lines to clean and maintain a mine. The air gets contaminated with lethal minerals that aren't good for you such as plutonium. Land erosion than occurs when so much land has be excavated from the ground and destabilizeses a foundation in which used to be called a park, a house, or a place to walk on. The land than collapses and causes damage for the locals.

regarding the law, the 15th amendment was specifically designed thinking in the rights of black free men.

even though ratified on february 3, 1870, the promise of the 15th amendment would not be fully applied for a long time.poll taxes and literacy tests would allow southern states disenfranchise african americans. only in 1965 the voting rights for african americans would be actually able to vote in the south.

in 1965, president johnson signed the voting rights act, which aimed to overcome legal barriers that prevented african americans from voting as it was guaranteed by the 15th amendment to the u.s. constitution.

the american civil war was not caused   by slavery but by economic factors.