Article VII stipulated that nine states had to ratify the Constitution for it to go into effect.
Answer: to prevent the legislative branch from having to much power
The bicameral system is supposed to provide for checks and balances and prevent potential abuses of power.
They both explored the new land in the Louisiana Territory--Pike found the source of the Mississippi and Lewis and Clark discovered routes to the Pacific Ocean.
The explorations of Lewis and Clark are seen as more valuable because they found routes to the west which would allow more people to move west. They made connections to Native American groups and help to map out the western territory.