what evidence exist that the southeastern U.S. once belong to Mexico?

SouthEASTERN? do you mean SPAIN instead of Mexico?

Please clarify.

Do you not mean the southWEST?

To determine if the southeastern U.S. once belonged to Mexico, it is essential to examine historical evidence. Here are steps to gather relevant information:

1. Research historical records: Delve into primary and secondary sources such as official treaties, historical documents, and accounts from the time indicating territorial claims or transfers between Mexico and the U.S. Locate sources specifically related to the southeast region.

2. Study border treaties: Analyze relevant treaties that delineated the borders between Mexico and the United States. The Treaty of Guadalupe Hidalgo (1848) and the Gadsden Purchase (1854) are two critical agreements outlining the territorial divisions in the aftermath of the Mexican-American War.

3. Examine historical maps: Review historical maps that illustrate the territorial boundaries during different time periods. This includes examining maps from Mexican rule, through the Mexican-American War, and after the signing of the aforementioned treaties.

4. Consult historical experts and scholars: Seek the insights of historical experts or scholars who specialize in the region and period in question. They can provide valuable interpretations of the available evidence and offer guidance on further research.

5. Evaluate cultural and linguistic influences: Examine cultural and linguistic influences in the southeastern U.S. Such influences from Mexico, including place names, architectural styles, food, music, or traditions, can indicate historical connections between the two regions.

By undertaking these steps, you will be able to gather evidence and draw conclusions regarding whether the southeastern U.S. once belonged to Mexico. Always critically assess the reliability and credibility of the sources used as historical evidence can vary in accuracy and interpretation.