Although John Chadwick decides at the spur of the moment to enlist with Jeff at Leavenworth, he has thought about joining for awhile. He knows he has brothers who can help on the farm in his place, he had planned to join up at Sugar Mound, and he has tried to get his father's permission for six weeks. He says, "I'm eighteen year old and I want to see the world" (Chapter 3). John enlists with Jeff out of a spirit of excitement, adventure, and perhaps just a bit of youthful rebellion.
David Gardner is caught up in the excitement of war sentiment also, but his decision to join up doesn't show the forethought and maturity of Jeff's and John's. David's decision is almost like that of a young, spoiled child - it's just something he wants to do, and he runs off with no regard for his mother's feelings or the fact that he, unlike John, is sorely needed on the farm. His immaturity is highlighted when he finds he dislikes the military and runs crying back home, only to be firmly forced to keep his commitment by his mother.