Original sentence: The South was dominated by a settled plantation system based on slavery, with rapid growth taking place in the Southwest such as Texas based on high birth rates and low immigration from Europe.The origins of the American Civil War lay in the complex issues of slavery, competing understandings of federalism, party politics, expansionism, sectionalism, economics, and modernization in the Antebellum Period
Edited sentence: The origins of the American Civil War lay in the complex issues of states rights,a national tariff, competing understandings of federalism, party politics, expansionism, sectionalism, economics, and modernization in the Antebellum Period and later the issue of slavery in the western territories.While fewer than 10 percent of white southerners owned slaves, the South was dominated by a settled plantation system based on slavery, with rapid growth taking place in the Southwest such as Texas based on high birth rates and low immigration from Europe.While the radical Republicans and many northerners wanted to keep blacks out of the new territories altogether