Hey I recently got a passport and Im going to be doing some traveling. When I was younger I commited a crime, Theft under $5000

My Girlfriend is pretty parranoid that I will be rejected at the airport, She believes i wont be allowed into the states. The
flight goes threw the states and then off to Cayman Islands. Ive tryed to call the place where i got my passport from but theyre closed till monday. I would just like to know if anyone out their would have any idea about this.
also if anyone knows about a website/place i can call where I can prove to her this isnt the case that would be swell