PS: The first US colonies actually took a crazy amount of capital to set up. The west was largely settled by people in covered wagons which for the time period also represented a lot of capital ~50,000+$ in 2018 USD.
But the west was first colonized by the Spanish.
One of the first Anglos to reach Alta California was the Bartleson-Bitwell party https://en.m.wikipedia.org/wiki/Josiah_Belden
For example, basically all of New England that isn't on the coast was settled by people who got so fed up with the puritanical authoritarians in Boston that upending their lives and moving a few days ride west (and risking starvation/financial run in the first few years) was the better option.
The underground railroad gets a lot of coverage, but it's peak never reached 1,000 slaves per year where 23,191,876 slaves where part of the 1850 sensuous. So, people are talking about a migration of ~0.004% per year.
Cheaper land makes being a farmer vastly easier. The same capital allows for more either more farm land or better farm land. Remember, farms are just like any business you can extract more money when the output stays the same but your costs drop.
Also, saying significant wealth is required to setup a colony is very different from individuals having that wealth. Consider the wealth required to build a 80 story high rise generally vastly outstrips the wealth of people living in it.
PS: That said, looking at modern immigration even illigal immigrants to the US tend to be better educated than the average peopulaion of their origin countries. Likely becase immigration is a lot of effort, weeding out the less motivated and capable.
Twenty-two dollars.
That adds up quickly.
"Back-breaking" isn't just a figure-of-speech; modern medicine isn't (yet?) advanced enough that a rational actor should ever choose construction work over something else; and there are just enough desperate people around that I doubt anyone is willing to pay the true cost of construction-work to a not-as-desperate would-be construction-worker.
The limited resource here, then, is actually: desperate people who are still smart enough to do construction work.
I can't wait until construction becomes a non-human-powered activity - even if it still requires a human to control the machinery.
That trend is so powerful precisely because lots of trade-working parents don't want their kids to suffer the kinds of medical bills, chronic pains (with potential resulting opioid addictions) and stunted healthspans, that they do.
Granted, construction is rather especially bad among the trades in this manner: things like welding are not quite as physically-demanding.
Their homes would do quite nicely as office-parks or some other commercial property, but those people both are rich enough and value their places irrationally enough, to [pay out their butts, and/or lose out on a big payout, to] stay there instead of taking their share of what developers think they can earn from that land.