It increased their population sizes, since farming could feed more people than hunting and gathering (the method used before the Neolithic Era).
The event that marked the end of the Roman Republic is often attributed to the defeat of Marc Antony in 31 BC at the Battle of Actium which ended the period of civil war.
Whigs were radical, and although their ideals did not completely take over England, the American colonists were affected by them.
Republican ideals have not completely taken over, but they were a major force in the Revolution. It has been referred to as the "last great act of the Renaissance".
Im assuming that you are asking about the Constitution. Article 2 section 4 of the Constitution literally says, “The President, Vice President and all civil officers of the United States, shall be removed from office on impeachment for, and conviction of, treason, bribery, or other high crimes and misdemeanors.”
