What does Howard Zinn say about how and why the United States took the Southwest (or northern lands of Mexico) from Mexico?

The
Mexican War is the subject of Chapter Eight of , and Zinn's narrative of
the conflict focuses on the intense opposition to the war among abolitionists and Whigs who
opposed the expansion of slavery. These critics viewed the war as immoral, an unjustified act of
aggression that many believed was aimed at the expansion of slavery into territories gained by
the defeat of...