Congress that they deemed unconstitutional. The Nullification Crisis arose as a result of the Tariff of 1828, a set of high taxes on imports of manufactures, enacted by Congress as a protectionist measure to foster the development of domestic industry, primarily in the North. In 1832, the legislature of South Carolina nullified the entire "Tariff of Abominations", as the Tariff of 1828 was known in the South, prompting a stand-off between the state and federal government. On May 1, 1833, President Andrew Jackson wrote, "the tariff was only a pretext, and disunion and southern confederacy the real object. The next pretext will be the negro, or slavery question." Although the crisis was resolved through a combination of the actions of the president, Congressional reduction of the tariff, and the Force Bill, it had lasting importance for the later development of secessionist thought. An additional factor that led to Southern sectionalism was the proliferation of cultural and literary magazines such as the Southern Literary Messenger and DeBow's Review. Sectional parity and issue of slavery in new territories Another issue feeding sectionalism was slavery, and especially the issue of whether to permit slavery in western territories seeking admission to the Union as states. In the early 19th century, as the cotton boom took hold, slavery became more economically viable on a large scale, and more Northerners began to perceive it as an economic threat, even if they remained indifferent to its moral dimension. While relatively few Northerners favored outright abolition, many more opposed the expansion of slavery to new territories, as in their view the availability of slaves lowered wages for free labor. At the same time, Southerners increasingly perceived the economic and population growth of the North as threatening to their interests. For several decades after the Union was formed, as new states were admitted, North and South were able to finesse their sectional differences and maintain political balance by agreeing to admit "slave" and "free" states in equal numbers. By means of this compromise approach, the balance of power in the Senate could be extended indefinitely. The House of Representatives, however, was a different matter. As the North industrialized and its population grew, aided by a major influx of European immigrants, the Northern majority in the House of Representatives also grew, making Southern political leaders increasingly uncomfortable. Southerners became concerned that they would soon find themselves at the mercy of