So don't set out and try to shoot a high contrast shot unless you find a good opportunity with the right lighting. Try shooting on an overcast day. It will soften the whites and blacks and result in a B&W image with more depth and gradient between the light and shadows.

The reason why the photographer chose to manipulate the picture was because he wanted to create a coping mechanism for the soldiers and the civilians during the civil war.

White balance (WB) is the process of removing unrealistic color casts, so that objects which appear white in person are rendered white in your photo. Proper camera white balance has to take into account the "color temperature" of a light source, which refers to the relative warmth or coolness of white light.