Among other things, the Nullification Crisis showed how tenuous the Union was. Angered by the failure of President Jackson to deal with the issue of tariffs and their damaging effect on the Southern economy, a number of important politicians, most notably Jackson's Vice-President, John C. Calhoun, openly defied the authority of the Federal government.

Many had fondly thought that the precise relationship between the Federal government and the states had been fixed by the passing of the Bill of Rights. But the Nullification Crisis showed that that wasn't the case. The states, especially those in the South, still had a distinct identity and were thus more than willing to stand up to the Federal government in defense of what they saw as their inalienable rights.

The aggressive response of the Jackson Administration provided a foretaste of how the Federal government would react thirty years later to the secession of the Southern states in the wake of Abraham Lincoln's election. Jackson wanted a compromise with South Carolina but was prepared to use armed force if necessary to enforce the will of the Federal government. Prescient observers noted that, if a similar crisis broke out in future, then a similar threat of force would need to be made in order to keep the states in line. And so it proved.

During the Nullification Crisis, South Carolina threatened to secede over what it referred to as the "Tariff of Abominations." The South rejected high tariffs, viewing them as being put into place to protect Northern manufacturers. The South resented the higher prices paid on imports because it was largely an agricultural economy. South Carolina rejected the tariff hike and stated that it would leave the Union if forced to collect the tariff.

This conflict was interesting, since the proposed leader of a seceded South Carolina was John C. Calhoun, the vice president of the United States. Andrew Jackson threatened to lead a column of troops to ensure South Carolina's compliance with the tariff collection and to make sure that the state did not leave the Union. South Carolina ultimately backed down when no other Southern states joined it in secession. The Nullification Crisis was important, as it saw the United States coming close to civil war nearly three decades before it actually happened. The crisis demonstrated that the federal government was willing to use force to ensure that states followed federal rules. Politically, Calhoun was not retained as vice president for Jackson's second term; Jackson went on to pick Martin van Buren, who would become Jackson's successor in 1836.

The Nullification Crisis was majorly an issue between the southern states especially the state of Carolina versus the Northern states. This was because the tariffs passed by the federal government seemed to work for the North against the South. The South being a consortium of agriculturally based states was going to suffer since the tariffs favoured the manufacturing states of the North with regards to their products. At the risk of war, leaders in Carolina pushed the agenda of nullification and secession of the Southern states. A compromise was reached between the government and the state of Carolina that averted the gridlock.

The issue of "state rights" was not fully dealt with at this point and morphed into a serious altercation between the states and the federal government that eventually led to the American civil war of 1861. As mentioned by rrteacher the Southern states tried to defend their slave policies because their plantations heavily relied on the slaves but the federal government under president Abraham Lincoln was bent on freeing the slaves. The Southern states decided to secede and form the Confederate States of America this was viciously opposed by the Union (United States) leading to the civil war that ended after the Confederacy was vanquished. This can be considered as the major impact of the Nullification Crisis on the United States.

The most important effect of the Nullification Crisis was that it demonstrated to ultras in the South that nullification would not be a viable way to exert their will on national politics in the future. The issue that caused the event was the passage of a series of protective tariffs that were deemed injurious to Southerners planters, but historian William Freehling showed almost 50 years ago that what really underlay tariff concerns were anxieties about slavery, particularly in light of increased abolitionist agitation in the North. They feared, as Freehling clearly showed in the internal debates over nullification in South Carolina, that the new tariff might set a precedent for federal action against slavery.

After South Carolina backed down from their extreme position, it became obvious that nullification was essentially a dead letter. Southern radicals, particularly those in South Carolina, came to believe that only the threat of secession would be an effective political tool in the future.