What is the cause of slavery and the effect for racism. for imperialism

The US desired African for their slave trade. People during this time were very racist and viewed the Africans as inferior, due to their skin color. As a result, they were exploited and puro work under strenuous conditions. Fun fact, plantation owners actually started using the native Americans as slaves, but they eventually stopped because they were too weak to work under the hard labor they enforced. So, the Americans engaged in triangular trade where they would send ships to trade goods and commodities with Europe, then from Europe to Africa, where they would trade goods such as rum and commodities such as mirrors in exchange for African slaves. The African slaves were naturally stronger and had a greater capability at working under difficult circumstances. The us desire for cheap labor is what drove slavery; the Africans were almost viewed as inhumane since they were black. Plantation owners always encouraged the slaves to reproduce with one another, that way once their children get old enough to work, they’ll either sell them to other plantation owners or have them work on their plantation for little to no pay. Plantation owners were benefiting off of the slaves hard work, gaining capital and hardly paying their slaves the currency they deserved.