There’s an interesting counter-factual blog post making rounds since the middle of the month. The question is posed – why were there no tanks in the Civil War?
The author of the piece, Jason Torchinsky, approaches this a respectful and practical stance. He points out that the underlying technology needed to produce a tank (more properly armored fighting vehicle… but tank is the handy expression) existed – armor, rotating turret, propulsion systems. And just looking at those photos of Petersburg’s trenches, some steam-powered proto-tank would seem like the thing for Ulysses Grant to take the war to Bobby Lee. Or maybe for Uncle Billy to finally break the defenses of Atlanta.
So the question is why didn’t anyone offer up a tank for use?
Well, long story short, because neither side needed a tank.
To expand on that a bit, consider the situation that created the need for tanks in World War I. It was not just the trenches that confounded military commanders. As I’ve pointed out in the discussion of field fortifications, those trenches, obstacles, and other features existed before the Civil War. And military science taught techniques to deal with those fortifications. So what was different on those French battlefields of 1915?
If we look at the tactical level, technology had given the defender multi-fold increases in firepower. The machine gun gets a lot of attention in this regard. But it was long range, rapid fire artillery that brought the most change to the battlefield. In order to counter the higher level of firepower that inhibited maneuver, generals sought a way to move their firepower up with the advancing infantry. So we have one “need” that the tank addressed.
Now I mention artillery. With even the lightest field pieces out ranging the largest Civil War pieces by a factor of three or four, the gunners were well outside of rifle range. Such brought depth to the battlefield well beyond what the Civil War generals had to deal with. Add to that the buzzing biplanes ranging well behind the front lines. All of which, again, inhibited maneuver, but here the consideration is at the operational level. And yet another “need” the tank could address. Let us stop the upward spiral there, but understand there were some strategic considerations also weighing into this “maneuver” problem.
What occurred between 1914 and 1916 was a confluence of technological capability and military need. That confluence was needed for the tank to be “invented.”
Was that same, or a similar, confluence working up in 1863-5?
It was not. The trenches at Petersburg and Atlanta (as well as those at Vicksburg the year before) were due in large part because of successful maneuver. In those cases the Federals had maneuvered their opponents into a point which could not be relinquished without grave effects. One cannot maneuver the enemy out of a position he is unwilling or unable to retreat from. And thus the campaigns took a static form. Simplistic overview, but we need not get too far into the mud.
Maneuver and firepower remained at the same relative levels throughout those campaigns (more or less where things had been at the start of the war… and twenty years before the start of the war). Not to say Civil War generals could maneuver at will, but rather to say the arithmetic for successful movement had not changed. The commander of 1864 could achieve a maneuver success by way of applying the tried and true practices… though we all know how fleeting success can be on the battlefield. Thus there was no confluence of technology and need. And thus no tank.
But… if we really want to start down the path of debating the practicality of armored fighting vehicles in the Civil War, and stay within the scope of military science then we have to bring up the “L-word.” Could the Civil War armies have sustained a force of tanks, logistically? Um…. probably not. At the height of the war, the US Navy was always “just” getting by with the supply of coal for the blockade (arguably the greater threat to the blockade, short of foreign intervention). And coal would be the most likely fuel for some hypothetical Civil War tank. Might Mr. Lincoln been confronted with a conundrum – “Sir, you can have your fancy armored wagons, or you can have your blockaders, but not both.”