That wasn’t an attempt at an insult. It was an observation that this stuff is usually covered in school. I should not make that assumption since I pulled my old textbooks many years later and finally got around to paying attention and reading through them thoroughly. From the get-go many of the founding fathers were very much against slavery and explained at length that that it totally did not satisfy the values laid out. Locke unfortunately didn’t fully rid his narrative of the institution either, claiming that certain situations called for it; mainly prison systems. The 3/5ths compromise happened at the constitutional convention because the south was too dependent upon their slave economy and actually was more afraid of what it would look like to set them free, realizing at the time that slaves were actually less economically viable than day laborers. You are correct that this is a contentious issue that should not have been a values at the time. Hence why there was a whole war fought in large part to abolish it. To solidify that these documents serve our needs and values as they evolve, there was literally an amendment post-war. Abolition. The values in the core documents are intentionally vague. Life, liberty, and the pursuit of happiness. They are guideposts.