By Allen C. Guelzo
Christian Science Monitor
One hundred and fifty years ago, American passions over politics blew off the lids we usually keep in place on our political debates and turned a war of words into a war of arms. By its end, the US Civil War had taken the lives of 620,000 Americans – the population equivalent of 6 million today. And despite the emancipation of more than 3 million slaves, the war ended up replacing slavery with a century's worth of racist Jim Crow laws.