Why should The United States not have gone to war with Mexico?

Mexico never wanted Texas until thousands of Americans settlers showed up there and turned what was basically a wasteland into a thriving territory. Once that happened, Mexico suddenly wanted to exert more control and even tax the settlers. The US was not about to let that happen.

The US tried to settle the matter by simply asking for the land. Mexico said no, and it was actually the Mexican Army that shed the first blood.

So we went to war. And because we had to fight a war to get the land our citizens settled and improved, then once we won, we took not only Texas but AZ, NM, CA and parts of OK and CO too.

The Mexicans could have saved themselves a lot of trouble (and land they ended up losing) by just giving us TX in the first place when we originally asked for it. But they got greedy against the US, and they paid the price.

They lost loads of captains and soldier, however they still got the land and all of that. it also created a feud with mexico and america.