How likely is AMEX to give out a card to someone with limited credit history?

I'm looking to get a second credit card and I'm thinking of getting American Express. I'm eighteen so I've only had my card for a few months, but I pay off the balance each month. My credit history is very limited so I'm not sure if it would even be worth applying to American Express. Does anyone know if they have cards that would be approved for people with limited credit history?