Having started upstream on the Missouri River<span> from their </span>St. Louis<span>-area camp—where they had been preparing for the expedition since fall 1803—on May 14, William Clark and nearly four dozen other men met up with Meriwether Lewis on May 20. hth</span>
The removal of a large area of trees for human use
It started in the 1880's.
The three things that brought about the fall of Rome when they all hit at once are:
1. multiple civil wars
2. economic collapse due to inflation
3. repeated invasions from all over
Rome used to be the most powerful country that ruled most of the world, but over time, its strength started to wane. In the end, due to many reasons, such as these above, it was forgotten and gave way to new countries being created.