Here are two ideas:
First, you should
check out the current issue of storySouth, the magazine I edit--we're
featuring a nonfiction piece dealing with the Mississippi River and
Communism. The essay and pictures are by Tom Foley, a photographer who
grew up the son of American communists--an authentic "red diaper
baby"--and was deeply affected by the McCarthyism of the 1950s.
To try and understand his place in America, he spent several years traveling
the Mississippi River and taking pictures of it. Might be something
there you can use. You can link to the essay at http://www.storysouth.com/fall2002/fridaysaturday.html
Second, I live on
the Mississippi River up in Minneapolis and kayak it during the unfrozen
months. But while most people try to kayak or canoe the "scenic"
places, I go through the tunnels and drainages of the Twin Cities. You
get plenty of interesting sights exploring the sewers that empty into
the Mississippi (especially since many of them were built in the late
1800s and resemble some type of gothic-themed Disney World ride--except
for the smell, of course). You might want to consider exploring some
of the endless sewers that empty into the Mississippi; I can guarantee
you most documentaries about the river don't cover that.
Hope something here
Also, one note about
Tom Foley's pictures and essay on storySouth--
As the editor's note
to his essay says, storySouth only printed an excerpt from his recently
completed book. He does have other essays in the book that deal more
precisely with what he was searching for by exploring both the Mississippi
and his life as the child of American Communists. If you wanted, I could
get him to send you some of these essays.