When they 'went home' that was desertion. But they surrendered and were allowed to go home undisturbed by those that they surrendered to in a act of generosity.
Think about it real hard, and subtract all the big pile of dead people from "we wuz whipped" from the answer.
But you wuz whupped. The confederacy started losing the war almost from the first day, was at no time ever close to defeating the Union, and it just took 4 years for the corpse to hit the floor.
Under what theory? The troops were State troops, mustered by the State and furloughed by the State, no officer objecting to their going home. The Union had no authority over them, pretended or legal, theoretical or pracitical. The Union forces at Brownsville had just had their asses handed to them, and any serious Union effort was weeks, months away at the earliest. Both the Army of the Potomac and the Army of the Cumberland were in the Washington area and ready to go home themselves. Tell me another.
The confederacy started losing the war almost from the first day, was at no time ever close to defeating the Union, and it just took 4 years for the corpse to hit the floor.
In your own mind, Yank. You've got to stop believing your own propaganda, it'll rot your brain.
On the other hand........go on believing it. Don't let me stop you.