The 1854 founding of the Republican Party reflected the splintering of the dominant American political parties in the face of intensifying sectional conflict over the spread of slavery in the United States. The Democratic and Whig parties had dominated American politics from the early 1830s, successfully maintaining support in different sections of the country through their diverse platforms. By the 1840s and 1850s, however, new political factions emerged, representing more specific interests. The short-lived Liberty Party and Free-Soilers were single-issue parties opposed to slavery, especially to its spread into the western territories. The American Party, or “Know Nothings,” represented the voice of nativist Americans who wanted to limit immigration, especially that of Roman Catholics from Ireland and Germany.