Despite the lack of military training and discipline, the typical volunteer was highly motivated. For a Union volunteer at the start of the Civil War, the main motive was to save Democracy from being overtaken by a Southern Aristocracy (by 1861, a typical Southern plantation owner saw himself as "God's Natural Aristocrat"). About 30% of the CSA soldiers were slave-owners, with the majority of officers as such. But after decade-after-decade of slavery in the South, even poor white farmers that didn't own a single slave had an instinctive impulse against what was considered "Domestic Tyranny".
In theory, a soldier could fire three aimed shots in one minute with a rifled musket, but the reality (under fire) was one shot (maybe aimed, maybe not) every three-or-so minutes. Also, the gunpowder created black clouds, which blinded the soldiers; accuracy when firing a rifled musket was very rare in the Civil War. Also, ramrods nicked the rifling in the barrel, which led to greater inaccuracies. Despite the advances in rifling, the bayonet was still the "Queen of the Battlefield."
Adding to the inaccuracy with the rifled musket was the training of the soldiers; untrained and uneducated in military matters, volunteer officers trained volunteer soldiers, which inherently caused even more inaccurate shots when they fired their weapons . . . there were documented engagements during the Civil War where 1 in 500 Minie Balls hit anyone. The high casualties of the Civil War were due to far too many close engagements when both armies fired their rifled muskets at each other; the officers rarely used the bayonet to end the battle sooner, thereby reducing the casualties.
The Civil War didn't have anywhere near the numbers of cavalry soldiers used in European warfare. In Europe, the artillery started the battle, the infantry turned the tide, and the cavalry closed the battle. The mounted soldier was anathema to Americans, in part because of the tremendous systems-network costs involved in getting a soldier on a horse. Even in Washington's day, the American tradition of cavalry was that it was to be used for reconnaissance and scouting . . . neither the Union or the CSA had the kind of cavalry that could turn the tide of a battle, even if they chose to use them as the Europeans.
At the disposal of both armies were three types of artillery. The first was the long-range shell, which was timed to explode over the heads of the enemy with shrapnel; neither flight nor aggression was possible when this type of artillery was used. For mid-range was the solid shot; this "Flying Bowling Ball From Hell" was used for distances up to 400 yards, and many solid shots were fired at once. The canister (basically a huge shotgun) was the short-range artillery of last resort, able to fire 32 yards wide at a range of 100 yards. All artillery soldiers had to pace themselves, mostly so they wouldn't wear themselves down too much or too fast, but also to avoid overheating the guns.
The most common weapon of the Civil War was of course the rifled musket, but unless enemy armies were very close for an extended period of time (which happened far too often), the rifled musket was not a weapon that excelled in terms of accuracy. Artillery was the deadliest weapon in the arsenal of both the Union and the CSA, but the the effectiveness of the artillery decreased with the range of the enemy. By far, the two most under-utilized weapons of the Civil War were the bayonet and the cavalry, which meant that deadly battles became even deadlier, since neither the bayonet or the cavalry was used to end the extended carnage.