March is idealistic in a number of different ways, however it is important to realise the ways in which the novel shows that he loses his idealism as the story progresses. After all, he at numerous times, particularly when reflecting on the difference between what he writes in his letters to his wife and the reality of what is really happening to him, acknowledges that war has changed him from his former self. Consider the following quotation:
How often it is that an idea that seems bright bossed and gleaming in its clarity when examined in a church, or argued over with a friend in a frosty garden, becomes clouded and murk-stained when dragged out into the field of actual endeavor?
Here he clearly recognises that ideas conceived in the luxury of peace and privilege lose their clarity very easily when they are actually transported to the very messy and uncertain reality of life. It is therefore important to recognise the way in which March does have his idealism challenged. However, at the same time, he does remain idealistic in terms of believing in abolitionism and also refusing to accept rules, laws and customs when he feels they are injust. Note, for example, how he protests on behalf of the freed slaves at the plantation where he is sent to help. He has a number of arguments with Canning about how he treats his black workers as if they were still slaves, and his idealism shines through in the episode when the plantation is attacked and the workers are captured and taken back into slavery. He is, however, by the end of the novel, a man who has had his idealism brutally attacked, and it is hard to escape the conclusion that he has exchanged some of his idealistic views for a more realistic pragmatism.