30 years
It last for over 30 years until the Kansas-Nebraska Act of 1854
Roughly 30 million buffalo roamed the plains in 1865
Mexican American Civil Rights Movement
Answer:
Lewis and Clark's team mapped uncharted land, rivers, and mountains. They brought back journals filled with details about Native American tribes and scientific notes about plants and animals they'd never seen before. ... Many Americans did more than dream. The great westward expansion was about to begin.
