Default shipping country selection should only be Us

Just having a little trouble with Marketpress. For some reason, when checking out, the targeted country isn't selected as the billing country by default EG, my client's site is set to sell in US only, but at checkout, "selected one" is the default country selection, instead of United States Can this be changed at all?

The only country available to select is the US. My client only sells to the US, and so would like to be able to have US be the default country selection on checkout