Explanation:
The Neolithic Revolution, also called the Agricultural Revolution, marked the transition in human history from small, nomadic bands of hunter-gatherers to larger, agricultural settlements and early civilization. ... Shortly after, Stone Age humans in other parts of the world also began to practice agriculture.
B. Because the civil war in the United States did not start until the 19th century
The two main reasons why Douglass opposed john brown's plan to raid harpers ferry were that 1) He was sure the plan would fail and lead to many black deaths, and 2) He thought he would hurt the abolition movement by causing a backlash. Hope This Helps :)