While slaveholding was slightly less concentrated than in some Southern states, according to the 1860 census, more than 330,000 people, or 33% of the population of 992,622, were enslaved African Americans. They lived and worked chiefly on plantations in the eastern Tidewater. In addition, 30,463 free people of color lived in the state. They were also concentrated in the eastern coastal plain, especially at port cities such as Wilmington and New Bern, where a variety of jobs were available. The decades of tensions over issues of slavery would be the main cause of the Civil War.