Patriotism is a healthy, moral-ethical love of one’s country, its land, its people their customs and traditions. It is not accompanied by any desire to initiate force or violence against anyone. Thomas Jefferson and Robert E. Lee were patriots and men of high moral values and ethical principles. The Declaration of Independence, a secession document, and the Articles of Confederation are patriotic documents. Neither contains any suggestion for the initiation of force or violence against persons or their property against their will.
On the other hand, nationalism is the immoral love of one’s government and usually involves a desire to aggress against or tyrannize others. Abraham Lincoln, Lyndon Johnson, George W. Bush and Barrack Obama were (are) nationalists. The Gettysburg Address, the Pledge of Allegiance, the Presidential War Powers Act the (intentionally misnamed) Patriot Act are nationalist documents. All imply aggression against persons and property—force and violence applied by one group against other groups.