Yes, in Texas, anti-miscegenation laws still applied to Latinos (Mexican Americans) as they were usually defined as White. It was much more obvious depending on the dominance of Spanish or Native lineage.
This was documented in "Flores vs. State" (1910). The law stated that a "White" person, F. Flores, in this case being Mexican, was arrested with his wife, Ellen Dukes, as she had traces of African-American lineage.
Those witnesses who testified to the fact that the woman appellant married was of negro extraction were not aware of how near she was to purity of negro blood; they did not know whether she was within the specified degrees mentioned in article 347 of the Penal Code or not.
Normally it seemed to have worked out for many mix Mexican-African American couples in Texas, as many were able to mask their lineages easier due to already being of mixed race (also typically mixed with Native American). ["Dangerous Liaisons: Sex and Love in the Segregated South", Robinson]
Even if the state discovered that one of the parties in the
relationship had some racial mixture, the state would then have the
very difficult task of proving that the individual in question had
sufficient black ancestry. Such was the case in Flores v. State
Flores and Ellen Dukes were convicted but appealed their case. The ambiguity of her lineage helped the State reverse the small court's decision.
The couple appealed to the Texas Court of Criminal Appeals. Although the court acknowledged that Dukes had black blood, the court held that the state had failed to prove the degree of it.
It's cases like this that show the flaws of such a system of oppression based on racial lines, with mixed races, at some point the lines are blurred. The history of slavery in Texas was more forgiving since the Mexican government forbade slavery while Texas was still under Mexican rule. The anglo colonists brought their slaves with them, and after Texas Independence, it was reenacted by zealous landowners. San Antonio remained more lenient due to its Mexican population and later German populations being against slavery. Mixed feelings on slavery existing through the civil war, with the city voting against cessation from the Union. San Antonio’s complicated history as a Confederate supply depot
The largest city in Texas at the time, San Antonio’s population
separated into three roughly equal groups: Anglos, Germans, and
Mexicans. The three groups did not mix, although a distaste of slavery
and a resentment of the Anglo population, who held most of the
property, united the city’s German and Mexican citizens, Ellsworth
Robert Lee was not in the city when it rebelled, before being put back into order by Confederate hands. Twohig was a friend of his and they sympathized with one another over slavery.
Perhaps Lee felt a kinship with Twohig, who, according to Wood, was
suspected of being a Unionist sympathizer. Records show the Irish
immigrant purchased and freed several slaves.
You don't hear much about that in the history books. Please check out the links to read more.