How Can I Call From Belize To The United States Using A Cell Phone

I have a cell phone and Verizon I've been in Belize for a Few Days and I'm Trying to call my family in the U.S., drank everytime I dial 1-three-digit area code and my phone number, it says this number is invalid. I Thought The Country Code for the U.S. WAS one? On the cell phone it says roaming and I know it's going to Be $ 1.79 a minute, I just wanted to call to Quickly and see how everyone IS doing.