When nullification is spoken about, the most common point of reference is the crisis of 1832. However, there is much more to it than just the crisis, which happened in the state of South Carolina. Before we turn towards the doctrine, we will first try to understand the meaning of the word 'nullification' in the legal perspective. Nullification Theory The nullification doctrine states that any U.S. State can rightfully nullify or invalidate any law passed by the federal government, which the state government decides to be unconstitutional. If one looks at American history, it is clear that different sovereign states came together to form a Union. Since the states together formed the Union, the final authority in regards to deciding the limits of the power of the federal government rests with the states. In other words, the extent to which the federal government can exercise its authority will be decided by the state governments. This was also called the compact theory. It is important to note that any efforts by the government of any state to declare a federal law null and void have never been upheld. There is also an extreme case of assertion of sovereignty by the states, known as secession. In this, the state can decide to terminate its political affiliation with the Federal government. Who was the Most Significant Proponent of the Nullification Theory? The origin of the doctrine of nullification is said to be in the famous resolutions of Kentucky and Virginia. These resolutions were made in protest against the Alien and Sedition Acts. The foremost proponents of this doctrine were Thomas Jefferson and James Madison. They opined that the ultimate authority of interpreting the Constitution rested with the state governments, and that the state government should have the right to interfere to protect the citizens of the state from the unconstitutional laws passed by the federal government. Over a period of time, there were talks about secession after Jefferson's party came to power. It is important to note that the nullification theory came to be more associated with matters related to slavery. The nullification crisis took place in 1832. In this year, South Carolina undertook upon itself to nullify the tariff of 1832 law passed by the Federal government. Then, there was an attempt by the northern states to block enforcement of the pro-slavery Federal Fugitive Slave Acts passed in 1793 and 1850. Although the laws were not declared nullified, the actions were such that it nullified the effectiveness of the federal law. The issue came up again in the 1950s'. It was in response to the Supreme Court's decision in the Brown v. Board of Education case. According to this ruling, it was decided that racial segregation of schools was illegal. Almost ten schools in the South undertook different measures, whereby they preserved the segregation and did not follow the ruling in Brown. However, the Supreme court ruling, which said, "the Brown decision can neither be nullified openly or directly by state legislators or state executive or judicial officers nor nullified indirectly by them through schemes for segregation", put a stop to attempts of nullification. It is clear that steps taken by any state government to nullify a federal law are going to be futile. Ultimately, the federal law will prevail on the state government's preferences, and they will have to enforce the laws.