 The white population of the state had strongly supported the institution of slavery since the 18th century.Political leaders such as Democrats John Calhoun and Preston Brooks had inflamed regional and national passions in support of the institution, and many pro-slavery voices had cried for secession.On the outbreak of war, South Carolina had the highest percentage of slaves of any U.S. state at 57% of its population enslaved; 46% of its white families owned at least one slave.