This can be done using the Custom Script Assistant in WebEasy Professional
1) Click on the Country box to select it (two clicks may be required - one to select the form and another to select the Country box).
2) Go to the "Tools" menu and select "Custom Script Assistant".
3) On the screen that appears select "Text to Display"
4) Replace the line that says "Afghanistan" with this:
5) Replace the line that says "United States" with this:
[code]<option selected>United States[code]
6) Click OK.
...now preview your site. United States should be selected by default. Alternately, moving the "United States" line to the top of the list of countries will also work, but then the list will no longer be alphabetized.