Lewis Cass, the Democratic candidate for president in the election of 1848, served as Buchanan’s first secretary of state from 1857 until 1860. Cass resigned from the office after Buchanan refused to heed his advice on protecting federal interests in the South. Cass realized that Southern forces were close to moving on federal property and close to secession. Buchanan probably realized it too but chose to be more conciliatory toward Southern states. Jeremiah S. Black replaced Cass as Buchanan’s secretary of state.