Midwifery is probably the oldest of all medical professions and continues to be important even today. If you expect a modern midwife to be an old woman wearing a pointy hat and wielding a sack of herbs, however, you'll be disappointed.
Midwives do not have to be registered nurses, though some RNs are also midwives (they are called CNMs, or Certified Nurse-Midwives). The midwifery exam they take is identical to that of CMs (Certified Midwives), and there is some overlap in the subjects taught in a bachelor's degree in midwifery and nursing school.
Midwives, however, focus on gynaecology, obstetrics, and women's health issues rather than broader patient care and hospital duties. In addition, they receive specialist training in counseling expectant and new mothers on subjects like family planning, proper nutrition, and infant care.
In Europe, you can study to be a midwife in Ireland, the U.K, France, and the Netherlands. Several courses are presented in English for foreign students. Figuring out which are best for practicing in the U.S. can be tricky, though.
Three separate organizations are involved: the Midwifery Education Accreditation Council (MEAC), the North American Registry of Midwives (NARM), and the American Midwifery Certification Board (AMCB). In addition, each state has different laws regarding midwifery and these are currently undergoing major changes. (Covid-19 caused a spike in the popularity of home births and highlighted the value of midwives.)
The key thing, apart from checking whether or not your U.S. state recognizes the CM (Certified Midwife) qualification, is to pass the AMCB examination. This requires you to complete a midwifery course at an accredited U.S. institution. If you already have an acceptable European bachelor's degree, this will take anything from weeks to a few months.