The war of tomorrow, yesterday
By the 1860s, when the American Civil War was underway, the United States- at least the North, that is- was already gripped in the Industrial Revolution. Out of that economic, industrial, and social upheaval came a great many new technologies. Some of these were weapons. Some of these weapons were fundamentally different from any that came before in the way that they inflicted death and destruction upon the enemy.
The minié ball
Minié Ball design sheet with dimensions, as well as weight specifications for the projectile and charge.
Developed in 1849 by French army captain Claude-Étienne Minié, the Minié Ball was designed to replace and surpass the more traditional musket balls of previously-used muzzleloading rifles. Compared to a smoothbore musket, a rifle would have better accuracy, but it would take a lot longer to load musket balls into the barrel due to an awkward, improper fit. The Minié Ball was not only more accurate than traditional balls, but was way easier to load because it was smaller than the bore size of the rifles it was intended to be used in. The iron cup at the base of the bullet, when the weapon was fired, expanded as it traveled along the barrel, neatly and snugly fitting in the rifled grooves of the weapon. Its shape and design allowed it to be fired both way faster and more accurately than balls, allowing for the rifle's dominance on the battlefield to shine.
Multi-shot capability
The Civil War was among the very first armed conflicts in the history of warfare to use truly multi-shot weapons. In the wars before the Civil War, the closest thing that a soldier could come across was a weapon with multiple barrels, chambers, and actions. By 1863, repeating rifles, or firearms that could fire more than one shot through the action before reloading, like the famous Spencer Repeater carbine, were being designed and implemented primarily by the North during the conflict. They were accompanied by the first successful pistols with a multi-shot cylinder and a single barrel- the single-action revolver, first designed and produced in 1835 with Samuel Colt's design. Finally, the Gatling gun, designed in 1862 by Richard J. Gatling, was the first firearm to successfully be able to fire in sustained bursts- a true machine gun.
Artillery
An example of one of the field guns used during the Civil War.
Artillery are crew-served big guns that have a much greater caliber than typical small arms. The modern equivalents include rocket launchers like the SMAW launcher and M224 60mm Mortar cannon. However, back in the day, militaries relied heavily on field guns that could be moved with the marching armies into battle. Doubly so were ones that were mounted on wheels that made them more portable. They were instrumental in suppression of the enemy and had a distinct psychological effect.
Hogg, Ian Vernon. "Artillery." Encyclopedia Britannica Online. Encyclopedia Britannica, 28 Dec. 2011. Web. 19 Dec. 2016.
https://www.britannica.com/technology/artillery
"Civil War Weapons - Civil War Academy - American Civil War." Civil War Academy - American Civil War. N.p., n.d. Web. 19 Dec. 2016.
http://www.civilwaracademy.com/civil-war-weapons.html
History.com Staff. "Civil War Technology." History.com. A&E Television Networks, 2010. Web. 19 Dec. 2016.
http://www.history.com/topics/american-civil-war/civil-war-technology
"Minie ball." Encyclopedia Britannica Online. Encyclopedia Britannica, n.d. Web. 19 Dec. 2016.
https://www.britannica.com/technology/Minie-ball
The Editors of Encyclopædia Britannica. "Gatling gun." Encyclopedia Britannica Online. Encyclopedia Britannica, 9 Jan. 2012. Web. 19 Dec. 2016.
https://www.britannica.com/technology/Gatling-gun
Rattenbury, Richard C. . "Revolver." Encyclopedia Britannica Online. Encyclopedia Britannica, 18 Feb. 2015. Web. 19 Dec. 2016.
https://www.britannica.com/technology/revolver
https://www.britannica.com/technology/artillery
"Civil War Weapons - Civil War Academy - American Civil War." Civil War Academy - American Civil War. N.p., n.d. Web. 19 Dec. 2016.
http://www.civilwaracademy.com/civil-war-weapons.html
History.com Staff. "Civil War Technology." History.com. A&E Television Networks, 2010. Web. 19 Dec. 2016.
http://www.history.com/topics/american-civil-war/civil-war-technology
"Minie ball." Encyclopedia Britannica Online. Encyclopedia Britannica, n.d. Web. 19 Dec. 2016.
https://www.britannica.com/technology/Minie-ball
The Editors of Encyclopædia Britannica. "Gatling gun." Encyclopedia Britannica Online. Encyclopedia Britannica, 9 Jan. 2012. Web. 19 Dec. 2016.
https://www.britannica.com/technology/Gatling-gun
Rattenbury, Richard C. . "Revolver." Encyclopedia Britannica Online. Encyclopedia Britannica, 18 Feb. 2015. Web. 19 Dec. 2016.
https://www.britannica.com/technology/revolver