I'm guessing the point, other than an interesting history refresher, is that Mexicans aren't respecting the border established back then.
But, of course, they are. Mexico has claimed no US territory as their own, and the illegal aliens dang sure know when they've crossed the border. It is their goal.
The border is not in question.
It appears that their educational system, such as it is, is perhaps only slightly superior to our system of public education. lol