If you think that troops marched at each other with muskets and rifles in the Civil War because they were too dumb to maneuver, you're dead wrong. Civil War formations were the pinnacle of strategy at the time, allowing commanders to bring maximum force to bear at a crucial moment as long as they could think far ahead of their enemy.
Infantry in the Civil War typically marched in lines or columns, quite similar to their forebears in the Revolutionary War and War of 1812. This technique is sometimes ridiculed since it gives the enemy a long warning that attackers are headed for them. But these massed formations usually worked better for attackers than small groups, like those we use today.
Typically, unless there was particularly valuable terrain or cover nearby, troops that marched in small groups against an enemy were destroyed by the enemy's concentrated fire.
So, instead, troops marched in large blocks that would be recognizable to George Washington or Andrew Jackson. But warfare and the necessary tactics had changed a lot in the decades between those men leading armies and the Civil War.
The biggest surprise for Washington or Jackson would come when an attacking force drew within 400 yards of their target. That was when defenders would raise their rifles and deliver their first volley at the attacking force, 300 yards further than was typical for earlier soldiers.
Remember the old saying from the Battle of Bunker Hill, "Don't fire until you see the whites of their eyes"? That's a bad adage for the Civil War thanks to the increase in rifled weapons.
Rifling dated back to before 1500, but rifled weapons feature a spiraling groove down the barrel that increases accuracy but greatly increased load time. Most commanders and procurement officers went with cheaper, smoothbore muskets that could be fired much more quickly.
But improvements in manufacturing and metallurgy had made it much easier and cheaper to produce quality rifles and, probably even more important, French inventor Claude-Étienne Minié figured out how to create quality ammunition for rifled weapons that could be quickly loaded.
The Minié ball was slightly smaller than the barrel it would be loaded into, allowing it to easily slide down the barrel without getting caught on the grooves. But it had a small opening in its base, not unlike the small opening on the bottoms of most cans and bottles you see today. When the weapon was fired, the hot gasses would push into that little cavity and expand the bottom of the round, making it grip the grooves and spin as it left the barrel.
So, suddenly, infantrymen could fire rifled weapons just as fast as smoothbores while still enjoying the massive improvements in accuracy and range. For troops in defensive positions, this meant that they could launch multiple volleys while attackers were marching up. If there were walls, fences, or ditches in the way, like during Pickett's Charge at Gettysburg, each obstacle gave a chance for defenders to launch an additional volley.
The only way an attacker could survive these volleys is if they arrived with a large enough force to absorb multiple volleys until they closed the gap, then attacked with the survivors of the charge. When possible, there was a way for attackers to turn the power balance back in their favor: flanking.
Lt. Gen. Thomas "Stonewall" Jackson made his career partially thanks to his ability to drive his men to conduct quick and sometimes covert marches during battles, like those at Chancellorsville and Second Manassas. These marching skills allowed his men to flank the enemy, attacking them from the sides.
Formations in combat were typically quite wide and could not change their overall direction of fire quickly or easily. If a formation was able to hit its enemy from the side, the flanking force could bring all of its guns to bear while the soldiers who had been flanked could respond with just a few shooters on the edge of the formation.
The best way out of this was a well-organized retreat or, rarely, an advance past the flanking force. Attempting to stand and fight was nearly always a recipe for disaster.
But of course, with skilled infantrymen firing about 2-4 shots per minute, it was still quite common for competing forces to fire their weapons while in short ranges and then have to defend or attack with no time to load another round. Then, it was time for rifle and bayonet combatives.
The butt of the rifle was a great club, and the bayonet at the front was a slashing and stabbing weapon. If attackers and defenders closed into bayonet range, men would swarm one another and attempt to fight in small teams that would slash their way through enemies.
But there was one technology, deployed in limited numbers during the Civil War, that changed all of this. Repeating rifles could fire anywhere from six to 15 rounds without reloading, allowing them to hit rates of fire of 15 or more per minute. Like rifled muskets, they were typically accurate to 400 yards or more.
When employed, this allowed the men with repeating rifles to inflict severe losses on their enemy even when outnumbered. In some cases, a force with repeating rifles could even ward off a flanking attack since each rifleman at the edge of the formation could fire as fast as 10 musket-wielders.