Why are there whites and blacks in America: "?"

The foundation of America began with Columbus' discovery of America. After that, European countries began to occupy South/North America and establish their own colonies. Now that the American part of North America is occupied by Britain, people from many European countries begin to build their homes in that desolate place by boat. Because of the British control system, the local people launched a revolutionary war with Britain and declared their independence on July 4, 776. America was founded. The southern United States is an agricultural area. Growing a lot of cotton requires a lot of cheap labor. One of the sources is that traffickers cheat Africans in Africa. The whole ship was kidnapped to America and sold as a slave. This is why there are both whites and blacks in America. Slaves were finally liberated after the American Civil War (1861April12-1865 April 9). Slavery finally collapsed in America. /kloc-At the end of 0/9, in order to develop the western region, the United States built a trans-eastern railway, negotiated with the Qing Dynasty, and began to make extensive use of Guangdong coastal residents. China people began to establish themselves in the United States. In the development history of the United States, it has continuously accepted foreign immigrants and never stopped. Therefore, the United States has the largest ethnic group in the world. There are all races.