Laws are not created in a vacuum. They are used to address situations as they arise. The 14th amendment was passed to address the aftermath of the abolishment of slavery. Amending the Constitution is a long, arduous process and wasn’t done to confer citizenship on those born here to undocumented individuals seeking a fresh start. Their presence helped settle the frontier and they weren’t a burden to society. But freed slaves needed to be legitimized as citizens since they did not come to America of their own free will. The current revulsion to illegals rests on the shoulders of the Supreme Court who has ruled that they must be counted as residents, politically, they must be cared for medically and their children must be educated, etc. Add in blue state benefits, welfare, and they now have more benefits than citizens, often while not working. It’s time to remove the honey pot from the grifters.
It is normally a long, arduous process, but the 1866 congress had an advantage over most other eras. They had occupation armies controlling the Southern states, and therefore the Southern states would rubber stamp anything they were ordered to pass.
Using guns to force states to vote certain ways is not how the framers envisioned constitutional amendments, I think.
But that is how it was done.