Basically, the Army blew the levee to save a town, Cairo, IL, at the expense of (a few) homes and (lots of) farmland on the MO side. Maciej (HN user idlewords) mentioned it in one of his interesting blog posts[1].
The blog post asserts:
> The farmers downriver got their fields fertilized with rich river silt and are wealthier and more resentful than ever. Like so many beneficiaries of big government, they remain its implacable foes.
which I've never been able to source, though I've been curious about it. AFAICT most of the farmers left and never returned to the area.
[0]http://www.stltoday.com/news/local/columns/pat-gauen/saving-...
[1] http://idlewords.com/2015/07/confronting_new_madrid_part_2.h...