I wish Americans would understand the difference between migrant and immigrant and settler. Until the end of the 19th century, people were settles because they could go from the old world to the new world without legal papers.

At that point, throughout the world, govenrments decided that people needed 'papers.' That's when it changed from being 'settlers' to being immigrants.

To be a migrant means to go from place to place, not necessarily illegal. Migrants might have a temporary visa to work for six months of the year. They are not immigrants. They can also be illegal in that they crossed the border, legally or illegally and stayed.

I doubt your parents were migrants. They were immigrants. My late father went from Germany to South Africa - a legal immigrants. Actually a refugee, but still.

Refugees are different to migrants. They still need legal entrance, but they are accepted ont he basis that their lives are in danger in their home country.

That said, you are 100% correct. Humans are migrants when troubles start - be in winter or war or persecution or some sort of natural disaster. And they could move from country to country without legal permission being required. People went where safety and survival (finance) were.

I wonder, though, what would happen if everybody could enter countries and settle at will. I suspect Africa would arrive on the doorstep of America. It would destroy the economy. Economies are also protected by not having a massive influx of poor people who have no modern skills.

Good luck with London, by the way. My favorite city, and I'm due for a visit in a few weeks. You might find that America is not particularly liked.