"We were all taught in school that there was national unity during the Civil War," he opined.
Of course, there is never "national unity" about anything, especially war, democratic politics being what it is. When is the last time you heard of a unanimous vote expressing national unity in the U.S. Congress about anything? Even the vote to declare war on Japan after Pearl Harbor was not unanimous.
The myth of national unity during the "Civil War" was invented and cultivated by the history profession, the Republican Party, and the New England clergy in the post-war era to "justify" the killing of hundreds of thousands of fellow citizens in the Southern states; the plundering of the South during "Reconstruction;" the destruction of the voluntary union of the states and the system of federalism that was created by the founding fathers; and the adoption of Hamiltonian mercantilism as America's new economic system.
Any serious student of the "Civil War" knows that this is all absurd nonsense.