See http://www.mogenclark.com/clark/clarkres.php for Newspaper on microfilm at the Library.
The Sever - Clark County Library
207 West Chestnut Street
Kahoka, MO 63445
Phone number (660) 727-3262

One more source could be The Keokuk Public Library
210 North 5th Street, Keokuk, Iowa

The Keokuk Public Library Web page at http://www.keokuk.lib.ia.us/

My understand is there was only one issue of the Alexamdia newspaper dated 2/12/1857.

Hope this is some help
Bob Hartman