The issue with Trump, and this is a big issue, is that he's not a conservative.
The idea of America, was to keep power in the hands of the people & local, by limiting the Federal Government & its powers.
The Constitution explicitly limits Government in every ammendment & reverts all unmonitored power to the States.
Trump is a big government guy, who has chased away the intellectual & big business portion of the GOP with his proposed trade wars & MAGA nationalism rhetoric. I dont see him as a savior but more a band aid until a 3rd party can implement some long term solution to debt & social programs that are broken.
Now- it's true, the US had both slaves & child labor laws. But remember this was in a time that we had very little population, we needed productivity. And as mentioned before, automation was beginning to replace the slave labor by the early 1800s. Remember that chapter in the history book on Eli Whitney & his cotton gin? The problem that congress had wasn't ending slavery, that was already being phased out (1808 was last imported slave). The question was, do you pay the owners for the slave and if so, what do you do with millions of uneducated and broke freed slaves.
Enter Lincoln & the GOP. The United States only colony was called Liberia and it was established as a refuge to deport freed blacks to. About 35,000 freed blacks were relocated there by the time of Lincolns election, and his plan was to use federal money to pay plantations for their slaves and deport them, raising funds thru the Morell Tariff Act....except the Southern leaders had no interest in getting taxed on their outputs only to turn around and pay themselves, so they left the Union.
After the war, think about the depopulation that occurred, every remaining family had 8,9,10 kids, and by ww1 those kids had 8,9,10 kids as well....what do you do with so many kids when the family farm now has tractors, grist mills, self bagging operations & centralized collection/ instant pay outs at Co-Ops....well you send the most unproductive to the cities to make a few bucks by working for less sewing dresses or assembling cars or sealing roofs.
Now that effect was that it put older returning veterans out of work in the cities, who had families, and that spurred a decline in spending on what was a new idea of 'consumer packaged good', so government interferred and as usual the result was a disaster. Child labor laws went into effect, putting the kids back on the farm, and the Wagner act (FDR) took affect, allowing unionization in cities.
Farms suddenly had way more help than they needed, so they overfarmed, over produced and prices collapsed and so did US agricultural homestead values, enter the great depression....a government created disaster that would have resolved itself in 3 years, but FDR manipulated the Federal Government soas to get 3 elections before the war, and one more during.
Half the New Deal was declared unconstitutional, the other half Hoover had before congress in '31. And remember, the NYSE was under State jurisdiction in 1929, it wasn't Federal. Who was the governor of New York in '29? FDR.
