What courses must you take to teach ESL/ELL?

I would like to teach English As A Second Language (ESL) aka English Language Learners (ELL). It was told to me by the ELL teacher at my old HS to take the course for Secondary English and then have the state pay for the courses in ELL. But I also heard online that many states want you to get a minor in English or teaching english before doing ELL. I do NOT want to be a bilingual teacher (Spanish/English.) I simply want to teach standard ELL and then take that abroad. There is a HUGE need for english teachers throughout Asia, Europe, China, Japan, Africa, Mexico, South America... not to mention inside the USA as well! So, does anyone know what I can do to get a degree ONLY in ELL without having to get a degree as a basic english teacher first? I don't want to have to go back and forth to college. Also, I live in Missouri (MO) if anyone knows the laws for teaching ELL in my state. Thanks!