During The Constitutional Convention, James Madison suggested to have three branches. The legislative branch, the Congress, would make laws. The executive branch would carry out the laws. A judicial branch would settle legal arguments. This set up a system of checks and balances where all three branches had a distribution of power so that nothing could become more powerful than them. They were under the Virginia Plan, which provided for a national government for them.
The increasing population and urbanization have resulted into changes in the land use pattern. Large scale forests have been destructed to expand land for cultivation.