White supremacy wasn’t just an idea that arose out of the wicked mind of an ignorant hick who lived in the South during the 19th century; it was a commonly held belief in all of America and Europe. If you were an intellectual, more than likely you embraced a belief in white supremacy. Most of the Enlightenment philosophers held to this form of scientific racism.
The classification of humans into different races began with the scientific work of those like Carolus Linnaeus and Georges Cuvier who were primarily involved in the classification of plants and animals. Linnaeus divided homo sapiens into four people groups: Americanus, Europeanus, Asiaticus, and Africanus. Cuvier used only three divisions: Caucasian, Ethiopian, and Mongolian.
Although Linnaeus and Cuvier did not hold to white supremacist views, others would add their own views to the classification process. One of these was Charles White, who developed the idea that the races were ordered in a “Great Chain of Being,” and that each race had different parents who were created separately, meaning that all races did not have their origin in Adam and Eve. This view was a form of scientific racism called polygenism. Because of this belief, Africans could be classified as a sub-species of humanity.
This is why Thomas Jefferson, who used biblical language to write in the Declaration of Independence that “all men are created equal” could continue to hold slaves. Notice how Jefferson used scientific language in his Notes on the State of Virginia to describe black persons:
Their round eyes, their flat nose, their lips which are always thick, their differently shaped ears, the wool on their head, the measure even of their intelligence establishes between them and other species of men prodigious differences.
In order to give scientific and empirical credence to their white supremacist views, Samuel George Morton, author of Types of Mankind, a Harvard professor, and president of the American Academy of Natural Sciences, collected and measured the skulls of different racial “species” from around the world. We now consider the “science” called phrenology to be pseudoscientific—but it was once the cutting-edge science of the day.
It was this willingness to give precedence to science over and above the scriptures which led to the downfall of some in the Southern Baptist Convention. According to the writers of The Report on Slavery and Racism in the History of the Southern Baptist Convention, “the seminary faculty taught white superiority and the inferiority of black capacities for civilization. They did so with full confidence their views were the conclusions of empirical observations undergirded by leading scientific authorities.”  John A. Broadus, a professor and president at the Southern Baptist Theological Seminary, used the same “scientific” language of the Enlightenment philosophers to describe the different types of “negro.”
The typical negro, with thick lips, flat nose, protruding jaws, narrow and retreating forehead, is entirely distinct from the other two races, and vastly inferior in point of intelligence. For my part, I never saw one of these who could be regarded as very intelligent. 
Broadus, who claimed to be a Christian, gave precedence to science and reason over the truth of the scriptures. As a result, he was able to justify the enslavement of African Americans. If only he (and others like him) would have been faithful to the truth of the Word (not giving precedence to science that conflicted with the scriptures, especially Acts 17:26 which says God “hath made of one blood all nations of men for to dwell on all the face of the earth“), perhaps the church would never have had to carry “the stain of racism.” 
1] Thomas Jefferson, Notes on the State of Virginia (Richmond, VA: J. W. Randolph, 1853), 149-150.
2] John A. Broadus, “As to the Colored People,” Standard (Chicago), 1 Feb. 1883, 1. As quoted by Gregory A. Wills, et al. in “Report on Slavery and Racism in the History of the Southern Baptist Theological Seminary,” Dec. 12, 2018, https://sbts-wordpress-uploads.s3.amazonaws.com/sbts/uploads/2018/12/Racism-and-the-Legacy-of-Slavery-Report-v4.pdf.
4] A phrase used in the book Removing the Stain of Racism from the Southern Baptist Convention: Diverse African American and White Perspectives by Jarvis J. Williams and Kevin M. Jones (Nashville, TN: B & H Academic, 2017).