How Young Is Too Young To Get Married?

Some countries are known to force child brides into marriage a young as 14 years old. While Americans may be horrified at the thought, there are many young girls getting pregnant at age 14. Should we be preparing out teens for early marriage, since we haven't beenable to prevent them for early engagement in sex? How do you teach a teenager to be a wife or husband? Or is it impossible to be emotionally mature enough to get married in your teens, even though you're physically old enough to impregnate a woman or give birth to a child? How young is too young to get married?