In field fortification an enormous quantity of work was done during
our last war. Washington, Richmond, Nashville, Petersburg, Norfolk,
New Berne, Plymouth, Vicksburg, and many other cities were elaborately
fortified by field works which involved the handling of vast
quantities of earth, and, where the opposing lines were near together,
ditches, abbatis, ground torpedoes, and wire entanglements were freely
used. In some cases the same ground was fortified in succession by
both armies, so that the total amount of work expended, in this way,
would have built several hundred miles of railway. Around Richmond and
Petersburg alone the development of field works was far greater than
Wellington's celebrated lines at Torres Vedras. In all future wars,
when large armies are opposed to each other, it is probable that field
works will play even a more important part than in the past. The great
advantage of such works, since the introduction of the deadly breech
loading rifles and machine guns, was shown at Plevna, where the
Russians were almost annihilated in attempting to capture the Turkish
intrenchments.