David,
Midwest would actually be the Central Region. Alabama, Arkansas, Florida, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Michigan, Minnesota, Mississippi, Missouri, Nebraska, North Dakota, Ohio, Oklahoma, South Dakota, Tennessee, Texas and Wisconsin.
If you live in the Central Region you are a local within you city of 'Residence,' and you get to choose NY or LA as your production city, which you can also work as a local-hire.
Stephen,
You must join to work on a show under union contract, however you must be legally able to work in the US, to legally work in the US, you should hold a working visa more here: http://www.usimmigrationsupport.org/visa_h1b.html
US territories, Canada & Mexico is the arm of the ICG.
Only in Right-to-Work (RTW) states, can they flat out hire someone non-union to work on a union show. The signatory company must exhausts all union possibilities in a non RTW state before offering employment to non-union people.