A main principle of The Wealth of Nations is supply and demand. What this is about is that the economy or the businesses will find what the people want, and they will produce to the wants and needs of the people. And the companies will charge more because the people want them more.
"Equality of rights was given to slaves"
Slavery ended in the United States in the spring of 1865, when the Confederate armies surrendered. All slaves of the Confederation were freed by the Proclamation of Emancipation, which stipulated that the slaves of all the states that had split off from the Union would be free from that moment. The slaves of the border states and those of the parts of the South that were in the hands of the United States were released in December of that same year thanks to the Thirteenth Amendment. From this moment on, slaves were given equal rights, although they were not reflected at that precise moment if the foundations were laid for this to happen in the future.