The founding fathers failed to eliminate slavery because:

industry had made the u.s. the richest nation in the world at this time. the second industrial revolution caused growth in industry and transportation, which allowed increased trade between nations.

i believe the answer is: returns on investments, no wages

people who belong in upper class society would most likely get there by obtaining multiple source of income, which a certain percentage of ownership for businesses. since most of them are job creator, they would most likely get their money from profit, not wages.