Over the years I’ve seen a lot of people claim that Texas seceding was not about slavery, and I just point them to this and ask them what the Texas leaders actually meant when they said “She was received as a commonwealth holding, maintaining and protecting the institution known as negro slavery--the servitude of the African to the white race within her limits--a relation that had existed from the first settlement of her wilderness by the white race, and which her people intended should exist in all future time.”
Because apparently that little statement meant something differently in 1861 than it does today.
https://www.tsl.texas.gov/ref/abouttx/secession/2feb1861.html
DECLARATION OF CAUSES: February 2, 1861, A declaration of the causes which impel the State of Texas to secede from the Federal Union.
The government of the United States, by certain joint resolutions, bearing date the 1st day of March, in the year A.D. 1845, proposed to the Republic of Texas, then a free, sovereign and independent nation, the annexation of the latter to the former as one of the co-equal States thereof,
The people of Texas, by deputies in convention assembled, on the fourth day of July of the same year, assented to and accepted said proposals and formed a constitution for the proposed State, upon which on the 29th day of December in the same year, said State was formally admitted into the Confederated Union.
Texas abandoned her separate national existence and consented to become one of the Confederated States to promote her welfare, insure domestic tranquility [sic] and secure more substantially the blessings of peace and liberty to her people. She was received into the confederacy with her own constitution, under the guarantee of the federal constitution and the compact of annexation, that she should enjoy these blessings. She was received as a commonwealth holding, maintaining and protecting the institution known as negro slavery--the servitude of the African to the white race within her limits--a relation that had existed from the first settlement of her wilderness by the white race, and which her people intended should exist in all future time. Her institutions and geographical position established the strongest ties between her and other slave-holding States of the confederacy. Those ties have been strengthened by association. But what has been the course of the government of the United States, and of the people and authorities of the non-slave-holding States, since our connection with them?