Today's St. Mary Parish was once part of Louisiana's Attakapas County. In 1811, the Legislature of the Territory of New Orleans divided the Attakapas Region, thereby founding St. Mary Parish. Its geographical position and proximity to the Great Atchafalaya River Basin and the Gulf of Mexico, coupled with its abundant wealth of natural resources, played a major role in shaping the industrial dynamics of the parish.

Agriculture and sugar mills, carbon black plants, shipbuilders, fabrication firms and seafood processors are all part of the industry found in St. Mary Parish. Interstate 49 will soon be completed through the parish, enhancing industrial and retail expansion along that corridor. The Parish has two ports – one on each end of the Parish, strategically located to accommodate business, industry, and international trade. A regional airport located near Patterson has a 5,400-foot runway and a companion 4,400-foot seaway to accommodate seaplanes.

Health care is provided by two hospitals – Teche Regional Medical Center in Morgan City and Franklin Foundation in Franklin. A Parish Health Clinic and several health units are accessible to all residents of the parish.

Education in St. Mary Parish offers both college and vocational curriculums and a full-time gifted program for grades 3 through 12. Public and private choices are available. South Louisiana Community College and Nicholls State University have campus sites in the parish. Louisiana Technical College offers technical training in many occupational choices

St. Mary Parish's diverse culture, industry, and bountiful natural resources provide an abundance of sporting and recreational activities, making it a great place to work and live.