Texas was simply a state of Mexico. To encourage settlement, Mexico allowed immigrants to settle there. Mexico gave them land, in exchange for sworn oaths requiring the immigrants to be loyal to Mexico, become Mexican citizens, and obey Mexican laws. A group of immigrants from the US accepted the conditions and swore to uphold them. A few years later they rebelled against the Mexican government. The Mexican government sent in troops, and it was not long before the US got involved. Mexico lost 40% of its territory. The US gained Texas, Arizona, New Mexico, California, parts of Colorado, and all those nice cities with pretty Spanish names, like El Paso, San Francisco, Los Angeles, Santa Barbara, etc.

Crockett was an 'Indian Killer' from way back. Mexico was, and still is, a nation composed primarily of Indian (Native American) people, so Crockett was continuing his life's work, in a sense, when he found his death. Mexico, despite its massive territorial losses to the US remains, with the US and Canada, part of North America.

Crockett was not literate enough to write anything like the quoted segment. If that document is in the Congressional record, it was, like almost everything else there, inserted later, and actually written by the same kind of criminals who currently populate the White House.