Why I think the oldest American civil war veterans saw some of the most change in history

When thinking about our ancestors, have you wondered who saw the most change in history so far, and specifically, what are some of those changes? Here's my reasons for believing that some of the last surviving veterans of the American civil war saw, at least argueably, the most changes in our history, and it hinges on 5 main technological factors, along with an historical-political factor, not really in a particular order.

.Firearms. These people were born in a time when single-shot muzzleloading muskets and cap-and-ball revolvers were still in common use despite the rise of cartridge-loaded firearms and reliable repeaters. A few lived until the time that semi-automatic rifles such as the M1 Garand (and its many variants) and SVT-38/40 were just replacing manual-action, mainly bolt-action rifles, and were cheap enough, simple enough, reliable and overall, practical to have as standard issue to large military forces, and when we start to see practical, built from the ground up intermediate-caliber assault rifles such as the MKB-42, and the more common Sturmgewehr 43/44 and AK-47 (albeit the AK-47 wasn't common yet, and the Soviets kept quite about it until the Vietnam war) rifles come into service and be practical as opposed to earlier, less successful attempts to make assault rifles such as the Cei-Rigotti and Fedorov-Avtomat.
At the same time, the cap-and-ball revolvers I mentioned were replaced by cartridge loading revolvers, and later, semi-automatic pistols. The best pistol that a civil war veteran would live to see was the Browning Hi-Power, which is a bit dated but still decent and used handgun by today's standards.
Also at the same time, they would also see practical handheld automatic weapons, such as the Madsen machine gun, Villar-Perosa, the MP-18, Thompson submachinegun, and Browning Automatic Rifle come in, which are all automatic weapons that are compact and lightweight enough to be carried, fired and reloaded by 1 person without the help of anyone else, along with man-portable belt-fed machine guns such as the MG 08/15 and MG-42.
Before I round this up, I didn't forget smokeless powder, jacketed bullets and bottlenecked cartridges!
Interestingly enough, the 2 last Confederate veterans lived up until 1959. So, they just might've seen the AR-10, a weapon that is, technologically and literally, about a century ahead of the weapons they used during the civil war.

.Medical advances. You can read up on how during the civil war era, more people actually died from contagious diseases than directly in battle! During World War 2, we had working antibiotics such as penicillin and other medicines that really helped combat disease. During the civil war era, people didn't wash hands or medical equipment that often. So, a surgeon or doctor could drop a tool such as a bonesaw on the ground and do little to nothing to really clean it! But, by the World War 2 era, people regularly washed hands, clean medical equipment, and tried to keep areas where medical work was being done cleaner. Not to mention how blood transfusions existed at least from latter half of the 17th century, but didn't become commonplace until the early 20th century, which was the time when people figured out how to do it safely becuase giving someone the wrong blood type is actually very risky!

.Transportation. Back during the American civil war era, people often had to ride on animal-drawn wagons or ride in trains with manual mechanical brakes, wooden cars heated by coal, pulled by 4-4-0 American style locomotives riding on iron tracks. But, by World War 2, trains had more sturdy steel cars that were heated by steam, reliable engineer-controlled air/vacuum brake systems, and were now more often pulled by diesel locomotives riding on steel tracks. At the same time, average people can afford decent cars, and airplanes started to take over and helicopters and jets started to appear.

.Ship technology and design. Even though steam powered ironclads were did exist during the civil war era, wooden sailing ships were still common. After the turn of the 20th century, steel steam-powered ships were in very common use, and diesel-powered submarines were in use during World War 1.

.Communication. During the American civil war era, news was spread through word-of-mouth, newspapers and telegraph. After World War 1, it was spread by radio and television started to become common, and after World War 2, television became quite popular.

.Political history. Oh my goodness is this enormous! I encorage looking at https://en.wikipedia.org/wiki/19th_century from the 1850's onwards, and up untill the 1950's https://en.wikipedia.org/wiki/20th_century. I'm sorry, but this part is far too big for me to be willing talk about now.

With all of this being seen by these people, please, think about all of the change that has happened; you lived through a period of the rise and fall of dozens of countries. You saw how radically Europe is changing.
Yesterday, you hear about Europe and the United States annexing places in Africa and Asia. Today, you're hearing about those exact places winning a pinch of freedom.
Yesterday, you rode a horse that not everyone privately owned. Today, you ride a car that most people in your country can afford.
Yesterday, you rode a train that had manual mechanical brakes, wooden cars heated by coal, pulled by a steam locomotive and rode on iron tracks. Today, you're riding on a train with working air brakes (vacuum, if you're in other places such as the U.K.), sturdy steel cars probably heated by kerosene, pulled by a diesel locomotive and riding on steel rails.
Yesterday, if you had an infection, you were in fear for your life. Today, if you had an injection, a dose of medicine would probably stop it. Yesterday, you almost never washed your hands.
Today, you wash your hands on a daily basis.
Yesterday, if you wanted to get news, you had to find it through word of mouth and/or a newspaper. Today, you can simply turn on a radio or TV.
Yesterday, if you wanted water, you had to go to a well or manual pump to get it. To heat it, you must put it over a fire. Today, you can turn on a faucet and electric motors and automatic heating systems do that for you.
Yesterday, you shot a rifled musket that was single-shot and loaded from the muzzle. Today, you can shoot a rifle made out of a mixture of steel and aluminum, and had a plastic forend, pistol grip and buttsock, and can fire 1 round per trigger pull, or with a flick of a switch, bursts and up to full magazines.
Yesterday, you fought in a war where brother killed brother and neighbor fought neighbor over state's rights. Today, you see your countrymen, countrywomen and your descendents unite against some of the most evil people publicly known at the time.
Now do you get what I'm talking about?

So which generation or group of people do you think that saw the most change in history? Please leave it in the comments below!