Stephen, are you trying to claim that Lincoln was talking about Northern secession in his 1848 speech? Have you read most of the speech? If that is your position, that is quite a stretch, and one that I don't think can be defended at all.

"The Mexican War was not about Revolution, the conversations were not about Mexico having a Revoltution."

You're right...the conversations were about the border between Texas and Mexico. Lincoln's point during this part of the speech was that a "treaty-fixed boundary" was basically irrelevant to the crisis with Mexico since the disputed territory, he argued, belonged to whichever nation actually ruled over it.