Darren, Tim, and I recently did another podcast episode on Grant, and we will be on the lookout for it in the coming month. We covered the first part of Grant's military career in the Western Theater during the Civil War. We plan on talking more about Vicksburg and Chattanooga in the following episode. Finally, as I read more about the Second Battle of Corinth, I began to see how close the Union came to disaster in the Western theater. It is difficult to imagine how far back the capture of Corinth would have caused the Union. It would have put Grant's plans on hold to capture Vicksburg, which would have prolonged the conflict further. Corinth would have been recaptured at a methodical rate all over again. Thereby, a Third Battle of Corinth would come.
I am taking some time to read about sieges during the pre-modern era (1618-1870). In my dissertation, I claim that Cold Harbor was the beginning of trench warfare as we understand it today. However, its tactics and engineering came from sieges. It was to target a particular force kept inside a fort or settlement. James Faulkner best illustrates how these fortresses had three significant functions, "to secure frontiers and deter invaders, to provide magazines and store depots from which field armies can draw supplies and sustenance, and to act as a center of local government, a symbol of authority and center for tax-gathering activities." It was challenging for any attacker to take a fortified position, no matter its size of force, because the defenders could often pick off soldiers looking for the best avenues of approach and create "kill zones" for any coup de main on the fortress eliminating the mass of numbers. Time was also valuable to the defender because allies or other armies could aid the distressed defenders, driving away any potential threats. Finally, the attacker's risky coup de main could seriously weaken its offensive capability, allowing the defender to launch a successful sortie against their opponent. Sébastien Le Prestre, Marquis of Vauban perfected siegecraft in the 17th century under Louis XIV. He expanded the borders of France with impregnable fortresses designed with mass artillery that could break up any assault on the place. Therefore, fewer defenders were required to hold each city.
This slow and methodical approach to warfare dulled the French army of the 18th century, which relied on its defensive posture. Meanwhile, other commanders like Prince Eugene of Savoy and the Duke of Marlborough sped up operations, as much as 18th-century logistics permitted, to eliminate enemy armies in the field before they reached a fortress. This time-consuming process affected even men like Vauban, who became impatient with aspects of the siege, such as what happened at Namur. Fortresses were expensive, but entrenchments were cheap. In the Napoleonic Wars, the Lines of Torres Vedras served the Duke of Wellington well, forcing the French into an untenable position. It would take time to figure out new methods to break intimidating entrenchments as it would take a mixture of sapping, encirclement, and innovation to break defensive lines promptly that political necessity allows.
Question of the Week: Which engagement of the 20th century were entrenchments most effective?