In Birth of a White Nation by Jacqueline Battalora, what is the general idea about colonial laws and the cult of the Lost Cause?

The thesis of Birth of a White Nation is that "'white,' like 'race,' is a historical imposition given content and form through the proliferation of ideas imposed and claimed through law." In other words, the meaning of "whiteness," and in fact whiteness as a concept, has a history; that is to say, it has changed over time for a number of different reasons. Both colonial laws and the cult of the Lost Cause played a role in the development of the concept of whiteness.
The "colonial laws" in question were developed in British colonies in the Chesapeake and in the Caribbean. Battalora focuses on the Chesapeake, where she shows that concepts of race developed along with labor systems in Virginia. At first, the law did not really distinguish between races, but throughout the seventeenth century, as the flow of servants from the British Isles began to dry up, and the demand for labor increased with the expansion of the cultivation of cotton, the Virginia Assembly began to pass laws tying servitude to race. One major focus of the propertied classes in Virginia was the establishment of anti-miscegenation laws that banned sexual relations between the races. The child of a white man and an enslaved woman of African ancestry would be considered a slave. Over time, slavery became racial, hereditary, and permanent, and whites began to define themselves in opposition to their black workforce, using legislation to create legal categories of "blackness" and "whiteness" that did not really exist before.
The "Lost Cause" myth was a set of beliefs that emerged in the South after the Civil War. On the one hand, it glorified the Confederacy (the Confederate monuments that are so controversial these days are very much relics of the Lost Cause) and on the other, it erased slavery, and therefore African Americans, from the story of the causes of the war and of Reconstruction afterwards. This was deliberate—the South was held to be a white man's country, and the experiment in racial democracy that was Reconstruction was framed as a horrible, oppressive period. In short, it had a bearing on the definition of whiteness inasmuch as it was used to prop up the new Jim Crow society that was beginning to emerge, complete with very strict racial laws that defined blackness and, by extension, whiteness. Whites were held up as the only legitimate political actors and citizens of the United States.
https://books.google.com/books/about/Birth_of_a_White_Nation.html?id=M_e2WLcxvFgC&printsec=frontcover&source=kp_read_button