U.S. Land Grab of Mexican Territory in War of 1847 Based On a Lie

Boundaries of Mexico Before War of 1847

My teenage niece, who lives in Brownsville, lists her location on Facebook as "occupied Mexico," possibly being aware of the unjustified U.S. invasion of Mexico in 1847 which resulted in a huge land grab by the aggressor and in Mexico losing half of its territory.  The War of 1847 is called by an historian "the first war based on a presidential lie," obviously well before the U.S. invaded Iran because of non-existent "weapons of mass destruction."

James K. Polk, the U.S. president at the time, made up some nonsense about American citizens being killed in the region, which he referred to as "American territory."  

CBS Sunday Morning ran a piece on 5/5/2013 called "America's Forgotten War" detailing the current viewpoint of Mexican citizens, Americans who spoke out against that war and the general ignorance on the part of most U.S. residents of this portion of their country's history.  

Since the program mentioned Abraham Lincoln as one who opposed the invasion of Mexico, I found thiis Lincoln quote:

"When the war began, it was my opinion that all those who, because of knowing too little, or because of knowing too much, could not conscientiously approve the conduct of the President, in the beginning of it, should, nevertheless, as good citizens and patriots, remain silent on that point, at least till the war should be ended. Some leading democrats, including Ex President Van Buren, have taken this same view, as I understand them; and I adhered to it, and acted upon it, until since I took my seat here; and I think I should still adhere to it, were it not that the President and his friends will not allow it to be so."

Ulysses S. Grant, who participated in the invasion of Mexico later wrote in his memoirs:  

"I do not think there was ever a more wicked war than that waged by the United States on Mexico."

With the current discussion over revamping our immigration policies, it's instructive to note that if not for a war based solely on greed, much of the United States would still be part of Mexico.  Judging by the map above, the states of California, New Mexico, Arizona, Nevada and part of Texas were originally part of Mexico.