The 15th amendment allowed Black men to vote. It was ratified on February 3, 1870.
In general the common argument is "This development paved the way for the use of nuclear energy". There are of course cons to nuclear power as well, but these are known.
Answer:
The Zhou Dynasty became really large which caused it to be hard to control. The people of Zhou created territories with leaders for each, and these territories became to form their own political parties and not following those of Zhou