Setting locales fails

[brownh@hartford-hwp.com (Haines Brown)]

I tried to dpgk-reconfigure locales, and set environment and the
default to en_US.UTF-8. 

Now I get:

$ locale
locale: Cannot set LC_CTYPE to default locale: No such file or directory
locale: Cannot set LC_MESSAGES to default locale: No such file or directory
locale: Cannot set LC_ALL to default locale: No such file or directory
LANG=en_US
LC_CTYPE="en_US"
LC_NUMERIC="en_US"
LC_TIME="en_US"
LC_COLLATE="en_US"
LC_MONETARY="en_US"
LC_MESSAGES="en_US"
LC_PAPER="en_US"
LC_NAME="en_US"
LC_ADDRESS="en_US"
LC_TELEPHONE="en_US"
LC_MEASUREMENT="en_US"
LC_IDENTIFICATION="en_US"
LC_ALL=

I used to get en_US.UTF-8 for the values in this list.

When I try to save a document in emacs, the iso-latin-1 is tried as
language environment and fails, and so I'm offered a list of
alternatives. I type in iso-latin-1 but get the error:

perl: warning: Setting locale failed
perl: warning: Please check that your local settings:
	LANGUAGE = (unset),
	LC_All = (unset),
	LANG = "en_US"
   are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").