mississippi also says it seceded over slavery not hertiage not state's rights either.

Lucius Quintus Cincinnatus Lamar II was born and educated in Georgia and moved to Oxford, Mississippi, to establish a legal practice. He was elected to the U.S. House of Representatives in 1856 and represented Mississippi in both houses of Congress. A strong supporter of slavery, he resigned from Congress in January 1861 and returned to Mississippi where he wrote the official [Mississippi Ordinance of Secession]. He served as lieutenant colonel of the 19th Mississippi Regiment and, in 1862, was appointed as Confederate minister to Russia and special envoy to England and France.

49% of Mississippi families owned slaves. In the “[Declaration] of the Immediate Causes which Induce and Justify the Secession of the State of Mississippi from the Federal Union,” Lamar made Mississippi’s position on slavery clear.

“Our position is thoroughly identified with the institution of slavery — the greatest material interest of the world. Its labor supplies the product which constitutes by far the largest and most important portions of commerce of the earth. These products are peculiar to the climate verging on the tropical regions, and by an imperious law of nature, none but the black race can bear exposure to the tropical sun. These products have become necessities of the world, and a blow at slavery is a blow at commerce and civilization. That blow has been long aimed at the institution, and was at the point of reaching its consummation. There was no choice left us but submission to the mandates of abolition, or a dissolution of the Union, whose principles had been subverted to work out our ruin.” [read the full document https://medium.com/armedwithreason/in-their-own-words-mississippi-4c64cca0ac1e ]
Lamar returned to the U.S. House of Representatives in 1873. He represented Mississippi in the U.S. Senate from 1877 to 1885. Lamar was a staunch opponent of [Reconstruction], and did not consider freedmen and other Black Americans fit to vote. He [promoted] “the supremacy of the unconquered and unconquerable Saxon race.” From 1885 to 1887, he served as United States Secretary of the Interior and, in 1887, was appointed Associate Justice of the Supreme Court of the United States by President Grover Cleveland, proving old Confederate White supremacists never die, they just become Supreme Court Justices.