Excerpt from the Personal Memoirs of U.S. Grant, U. S. Grant (New York, 1885), pages 22-24.

Even if the annexation itself could be justified, the manner in which the subsequent war was forced upon Mexico cannot … the Southern rebellion was largely the outgrowth of the Mexican war.  Nations, like individuals, are punished for their transgressions.  We got our punishment in the most sanguinary and expensive war of modern times.   {end}