The soldiers and Henry are despondent because the army has not moved.
At the beginning of the novel, many of the soldiers are tired of waiting around to move. They have been in the same spot for too long and are getting antsy. They also don’t feel like they know what’s going on. They are lowly soldiers and are left out of the loop.
When the book opens, the Union soldiers can see the confederate soldiers’ fires in the distance. They want to go and fight, because they are tired of waiting.
“It's a lie! that's all it is—a thunderin' lie!” said another private loudly. …. “I don't believe the derned old army's ever going to move. We're set. I've got ready to move eight times in the last two weeks, and we ain't moved yet.” (Ch. 1)
Beneath the soldiers’ complaints about not moving is the hidden fear of when they do move and have to fight. Battle seems very close, and they are getting nervous. They act brave and complain, because waiting for nothing to happen is worse than fighting. When they are fighting they can be brave, but waiting to fight brings out the cowardice in even the best of them. Hurry up and wait is one of the realities of war.