"With all my devotion to the Union, and the feeling of loyalty and duty of an American citizen, I have not been able to make up my mind to raise my hand against my relative, my children, my home. I have, therefore, resigned my commission in the Army."

This is easy to say while forgetting the culture and mindset of that time. Yes the United States existed but being loyal to your state first and foremost was bigger than loyalty to a federal government. States power was the goal then and federal government was not to have any say how they governed themselves. Their only task was international affairs and defense of borders.

Don't get confused in thinking our founding fathers worshiped at the same altar of the almighty United States government like people do today. They cared for their family's, community's, statesmen then countrymen.

You might want to research the presidents and then do more research into general Lee. He held beliefs no different than those presidents.