If Slavery was ended earlier, it can affect how the family tree of one race can be affected with another. This can also represent a greater economy because of racism still going on in the years, And stopping it can cause for equal people to agree on something without someone saying something as a racial slur
Not only since if Slavery ended America could have gone a lot richer from a while ago such as how the actual capital stock rose by over 100% of GDP, But how other countries who already ended slavery a while ago had already had more money when workers had more freedom and rights themselves