Frame it any way you want, but he was disloyal to his nation. While an US Army man, he took an oath.
The residents of the states that seceded were no longer required to be loyal to the USA any more than the Founders, once they made the Declaration of Independence were required to be loyal to King George.
The Founders had no legal right to secede from England, but judged the British government to be oppressive, abusive, and non representative of the concerns and needs of the people. And it was the same oppressiveness, abusiveness, and non representative of the concerns and needs of the southern states that ultimately prompted their decision to secede.
From the Declaration of Independence:
"WHEN in the Course of human Events, it becomes necessary for one People to dissolve the Political Bands which have connected them with another, and to assume among the Powers of the Earth, the separate and equal Station to which the Laws of Nature and of Nature’s God entitle them, a decent Respect to the Opinions of Mankind requires that they should declare the causes which impel them to the Separation.
We hold these Truths to be self-evident, that all Men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty, and the Pursuit of Happiness—-That to secure these Rights, Governments are instituted among Men, deriving their just Powers from the Consent of the Governed, that
whenever any Form of Government becomes destructive of these Ends, it is the Right of the People to alter or to abolish it, and to institute new Government, laying its Foundation on such Principles, and organizing its Powers in such Form, as to them shall seem most likely to effect their Safety and Happiness. . ."
Whether or not the seceding states were right or wrong in their complaints is irrelevant. Their complaints were never addressed. In America's bloodiest war they were defeated and forced to remain in the union. They did not attain parity in political power until they gained sufficient population to be a political force.
But all sides of that debate should be part of American history and taught to every citizen who should understand it all and in the process understand the need for the electoral college and what the Founders intended the government to be.
To destroy or do away with historical monuments and markers that progressives don't like is not only unAmerican but irresponsible and borders on evil.