The easiest way you can check your Gold Delta SkyMiles Business Credit Card application status is on the issuer's dedicated page. Alternatively, you can check it over the phone, by calling (888) 826-3471.
You just need to provide your Social Security number and home address.
Ultimately, it's important to remember that if you're denied, there's still hope. You can ask for a Gold Delta SkyMiles Business Credit Card reconsideration of your application by calling (800) 567-1083.