To move this debate into the modern day arena, I wonder whether soldiers who refuse to fight in Afghanistan and Iraq in what they see as unjust wars are actually being intensely patriotic in terms of showing their opposition to a war that they think the USA should not be involved in. I guess it all depends on perspective and who decides what patriotism consists of.
Dissenters in WWI defined patriotism as isolationism, just as many had before. Going all the way back to Washington's Farewell address, we can see that often Americans have decided that what is best for the country is to not be entangled with anyone else's politics or war. While many dissenters are often pacifists, with their dissent a result of those beliefs, they consider it patriotic to protect their country from the evils of war. Any war.
Those who opposed the war were scarcely considered Patriotic. The most famous, of course, was Eugene V. Debs, who was jailed for violating the Sedition Act of 1917. His famous pronouncement on the war was:
I am opposed to every war but one; I am for that war heart and soul, and that is the world-wide revolution.. . . I would a thousand times rather be a free soul in jail than a sycophant and a coward on the streets.
The other notable dissenter was Jeannette Rankin, who cast the sole dissenting vote for a declaration of war in both world wars. Rep. Rankin was a pacifist and opposed to war at any time.
So, those opposed to the war were typically opposed on pacifistic rather than patriotic grounds. Prior to the U.S. entry into the war, some Americans of German and Irish descent supported the German side; but this rapidly dissipated with the propaganda campaigns of the Committee on Public Safety.
I would argue that the dissenters in WWI (like Eugene V. Debs) defined patriotism as a desire to do what was best for the country. This is as opposed to the more popular definition of patriotism, which would have been that patriotism is the feeling that you should back whatever the country is doing -- "my country right or wrong."
Debs did not simply back whatever the US government wanted to do. Instead, he criticized the war and he criticized the draft. He did not believe that the war and the draft were actually good for the country and its people as a whole. Instead, he believed that the war was an example of the upper classes exploiting the lower classes for their own benefit.
So Debs opposed the war because he thought it was not the best thing for the US. This would imply that he defined patriotism as the desire to work for the benefit of the country as a whole.