I have my Debian install set to boot to text mode.

When I type startx, gnome loads.

What do I need to change in order to get KDE to load?

Thanks.

startx is a front end for xinit. check out your ".xinitrc" file in you home directory. On my machine it's heald in $WINDOWMANAGER environment variable.

I dont have that file

Hmmm

To determine the client to run, startx first looks for a file called .xinitrc in the user's home directory. If that is not found, it uses the
file xinitrc in the xinit library directory. If command line client options are given, they override this behavior and revert to the xinit(1)
behavior. To determine the server to run, startx first looks for a file called .xserverrc in the user's home directory. If that is not found,
it uses the file xserverrc in the xinit library directory. If command line server options are given, they override this behavior and revert to
the xinit(1) behavior. Users rarely need to provide a .xserverrc file. See the xinit(1) manual page for more details on the arguments.

try:
man startx
and
man xinit