Which primary source document could a historian understand why the us civil war started? a map of the 1860 presidential election results a map showing where the first battles/ occurred a charleston mercury editorial published in 1860 /an essay that lists several possible causes

The right answer for the question that is being asked and shown above is that: "occurred a Charleston Mercury editorial published in 1860 " The primary source document could help a historian understand why the US Civil War started is that occurred a Charleston Mercury editorial published in 1860 

Where are the options?