The author cited below wrote: “Perhaps it was cold comfort to dismembered Mexico, but the “Mexican Cession” led in the next two decades to the death of a million gringos, as well as to sectional hatreds that persist to the present.” The Compromise of 1850 led to the political rise of Lincoln, John Brown’s violence, the formation of the Republican party, the election of Lincoln, the withdrawal of Southern States and war.
The Deadliest War
“The Deadliest war in American history, in terms of total deaths per thousand who served per year, at last was over. Of the 100,182 soldiers, sailors, marines who participated, only 1548 were killed in action, but 10,970 died from disease and exposure. Thus, the mortality rate was 110 per 1000 per annum (as compared with a Civil War rate of 65; a Spanish-American War rate of 27.79; and a World War I rate of 16. In World War II the death rate was about 3 percent of the total strength of the armed forces.
And the death rate was appallingly high in relation to the length of actual combat, for the conflict with Mexico lasted just twenty-two months (with only seventeen months of actual combat) . . . [and American soldiers] would continue to succumb to diseases contracted in Mexico for the next several decades. J.J. Oswandel, a veteran of the war, wrote in 1885, “After the close of the war we returned home with impaired health . . . with a disease contracted in a strange climate, which, in a few years after the war had taken from their homes more than half of those who returned.”
(North America Divided: The Mexican War, 1846-1848. S. Connor & O. Faulk. Oxford University Press, 1971, pp.170-171)