Marbury vs. Madison was a critical Supreme Court ruling in 1803 that established the notion of "judicial review" in the US by, for the first time ever, declaring an act of Congress to be unconstitutional. Chief Justice John Marshall, writing an opinion for the majority, essentially forced the Republican Jefferson administration to follow the letter of the law and officially commission Federalist judge William Marbury, who prior president John Adams had appointed to a judgeship before leaving office.

In this way, the principle of judicial review—in other words, a court's ability to strike down, modify, change, or legitimize laws created by Congress when evaluated according to a preexisting doctrine (like the US Constitution)—became a radical leap in power for the judicial branch, solidifying its status as a co-equal branch of government and as the ultimate arbiter of constitutional law.

However, such a decision did not end the debate over the judiciary's authority. In fact, it has ignited a firestorm for over two hundred years about the limits of the court's power and its role in government. While the principle has been defended as commensurate with the American system of government's commitment to adequate checks and balances, it has also been attacked on the grounds it allows a small cadre of unelected officials to overturn the will of duly elected representatives in the other branches with constitutional arguments that could be described, at best, as specious.

The main significance of Marbury v. Madison is that, for the first time, it established in the United States the principle of judicial review, the power of courts to strike down legislation deemed unconstitutional. The Supreme Court now had an important role to play at the apex of the American political system. Its decision highlighted and entailed the increasing importance of the judiciary in politics; from now on, matters of great political importance would be decided not just by "We, the People," but "Them, the judges." 

The Supreme Court's arrogation of power was also in keeping with a growing trend toward the centralization of authority in the American political system. A significant component of this process was the overriding of state by federal law. This case further accelerated this process. The Court was overwhelmingly Federalist and, as Federalists, the judges recognized that the increased power of the judiciary in American politics was a valuable tool in constructing the kind of country they wished to see established: a country with a strong federal government, pursuing a largely commercial economic agenda in which the interests of banks and corporations would dominate. This would necessitate the building of a structure of federal laws and regulations that the Supreme Court, thanks to Marbury v. Madison, was now in a strong position to enforce.

Very simply, John Marshall gave the Supreme Court the power of Judicial Review.  Now, the 9 unelected Judges on the Supreme Court had the power to declare a law passed by an elected legislative body either Constitutional or unconstitutional.

The significance of Marbury v. Madison is that the ruling in that case gave the Supreme Court of the United States the power of judicial review.  Judicial review is the power to determine whether a law passed by a legislature (in this case, Congress) is constitutional.  In Marbury, the Supreme Court took the power to declare that laws passed by Congress were null and void if they (in the Court’s opinion) violated the Constitution.

Before Marbury, it was not clear which branch (if any) of the federal government could interpret the Constitution.  The Constitution clearly stated that laws were invalid if they were not in accordance with the Constitution, but it did not say who got to decide if laws were invalid.  This was an important issue because the Constitution would not really have much meaning if Congress (for example) could make any law it wanted to simply by saying that the law was constitutional. 

In Marbury, the Supreme Court declared that a law passed by Congress (the Judiciary Act of 1789) was unconstitutional and it therefore said that the law could not be enforced.  This was extremely important in our history because it established that the Court could overrule acts of Congress that were unconstitutional.  This has had an immense impact on our history because it has allowed the Supreme Court to rule on laws that have had to do with everything from the price of hauling freight on railroads to child labor to abortion.  This has made the Supreme Court an important player in our history.

Marbury v. Madison is significant because it established judicial review. After President John Adams lost his reelection bid to Thomas Jefferson, Adams appointed a number of Federalist judges in the late stages of his presidency, and these judges came to be known as the “midnight judges.” One of this judges, William Marbury, did not have his appointment delivered before Jefferson took office, and Jefferson’s Secretary of State, James Madison, promptly halted the appointment. Marbury sued Madison, arguing that Madison did not have the power to stop delivery of a previous appointment.

The Supreme Court was led by Chief Justice John Marshall at the time, and the Supreme Court cited part of the Judiciary Act of 1789 unconstitutional as part of their 1803 ruling.

On the surface, this did not seem like a very important case, but the precedent of judicial review, or the idea that the judicial branch is the ultimate interpreter of the Constitution, is monumental because it solidifies the judicial branch as being on the same level of power as the executive and legislative branches.

Marshall was a Federalist and a political opponent of Jefferson, and many view this ruling as an assertion of power by Marshall to establish the judicial branch as an entity able to check the power of the other two branches, which it succeeded in doing.

The case of Marbury v. Madison established the precedent of judicial review. In the closing days of his presidency, John Adams appointed several justices that would become known as the "midnight judges." Adams did this out of fear that his successor, Thomas Jefferson, would change several laws. The incoming Secretary of State, James Madison, blocked one of the justices, William Marbury. Marbury then sued Madison in a case that reached the Supreme Court.

In the case, Marshall ruled that Marbury had a right to his judgeship since he was appointed by the outgoing president. Marshall also ruled that the Supreme Court could not assign Marbury his position. The case set the precedent for judicial review, the act by which the Supreme Court could decide whether or not a law was constitutional. This ruling gave the judicial branch a very specific job within the framework of the Constitution. It gave the courts a check on the legislative and judicial branches in that the Supreme Court could strike down laws that it deemed to be against the letter and intent of the Constitution.

For much of the nation's early history, the Supreme Court did not rule on many cases deciding the constitutionality of a law. The Marbury v. Madison case also established John Marshall as one of the key founders of the judicial branch.

Marbury v. Madison (1803) was an important case because it established the principle of judicial review—that is, the right of the Supreme Court to rule whether laws passed by Congress are constitutional. This case involved a man named William Marbury, who had been appointed to a position as justice of the peace by President John Adams just as Adams was leaving office. Marbury was among the so-called "midnight appointees" who were given offices right before Adams left office. When he assumed office, President Jefferson refused to honor Marbury's commission, and Marbury sued the Secretary of State, James Madison, in response. Marbury wanted the Supreme Court to order Jefferson to give him his office.

In his decision in this case, Supreme Court Justice John Marshall ruled that Marbury was entitled to his commission. He also ruled that the Supreme Court did not have the right to give Marbury this commission, as this right did not fall under their constitutional powers. Although this decision seemed at first to detract from the power of the Supreme Court, it actually enhanced the court's powers because they had the right to review the constitutionality of laws passed by Congress.

Marbury v. Madison was significant because with its decision in the case, the Supreme Court established the principle of judicial review. The case stemmed from newly-elected President Thomas Jefferson's refusal to allow his Secretary of State James Madison to deliver commissions for a number of lower-level judicial appointments made by outgoing President John Adams. One of the appointees, William Marbury, challenged Jefferson, claiming that the Judiciary Act empowered (required, even) the Supreme Court to issue a legal writ called a mandamus that would force the President and his Secretary to deliver up the commissions. The Supreme Court, headed by Jefferson's political adversary John Marshall, ruled that this part of the Judiciary Act was in fact unconstitutional. The case was very complex, and not in and of itself all that consequential, but the precedent established by Marshall--that the Court might rule a law passed by Congress unconstitutional--was a very significant one. Though the Court would not exercise judicial review for several decades, the principle of judicial review would over time become a pillar of the system of checks and balances in the U.S. Constitution. It was also one of several landmark decisions issued by the Court under Marshall, whose vision of a robust federal government would prove very influential.