Answer:
The Louisiana Purchase was a significant acquisition of land by the United States from France in 1803, which roughly doubled the size of the United States. It greatly expanded the territorial boundaries of the country and opened up vast new areas for settlement and economic growth. The acquisition of Louisiana also played an important role in the development of the American West and helped to establish the United States as a major world power.
Marbury v. Madison was a landmark case in which the Supreme Court established the principle of judicial review, which allows the court to strike down laws or executive actions that violate the Constitution. This decision strengthened the power of the judiciary and established the Supreme Court as the ultimate arbiter of constitutional questions. It also helped to establish the important principle of separation of powers, and reinforced the idea that no one branch of government should have too much power.