I’m not positive but I’m pretty sure they thought the land would be opened up for the Americans after the war but that was not the case and they were mad about that
There were few government regulations so businesses used ruthless tactics to eliminate their competition.
A slave rebellion in Haiti helped the United States double in size at the beginning of the 19th century. The uprising in what was a French colony at the time had an unexpected repercussion when the leaders of France decided to abandon plans for an empire in the Americas. With France's profound change of plans, the French decided to sell an enormous parcel of land, the Louisiana Purchase, to the United States in 1803.
I think that what Mandela means when he speaks of nation building is creating a world where everyone is equal and has rights. I think this because we know that there was a huge racial injustice at the time and Mandela was fighting for black rights. He also used the word reconciliation which means making a view or belief compatible with another or the restoration of friendly relations.
I hope this helped.