As the first credit union in United States, St. Mary's Bank is proud of its heritage. For just over a century, we've been helping New Hampshire individuals, families, and businesses with a wide range of financial products and services, including checking accounts, personal loans, real estate loans, business banking, and savvy financial planning. This Credit Union is federally insured by the NCUA. Equal Housing Lender. Equal Opportunity Employer/Protected Veterans/Individuals with Disabilities.