UnionPay started in China and was used mostly around Asia. They wanted to start their own network so they are sort of like Discover and JCB from Japan.
I don't think that any US banks issued those cards as there's no demand for them here. Perhaps, in Canada because they have a lot of expats from Asia.
UnionPay does have reciprocity agreements with most US banks and Discover. You're able to use their cards at over 90% of ATMs in North America. There's also an increasing number of merchants accepting it such as Amazon. Expect possibly a lot of fees just to manage to get one so it may not even be worth it.