Bay St. Louis is a city in and the county seat of Hancock County, Mississippi, in the United States. Located on the Gulf Coast on the west side of the Bay of St. Louis, it is part of the Gulfport–Biloxi Metropolitan Statistical Area. As of 2010, Bay St. Louis’ population was 9,260.

St. Bernard Parish (French: Paroisse de Saint-Bernard; Spanish: Parroquia de San Bernardo) is a parish located in the U.S. state of Louisiana. The parish seat and largest community is Chalmette. The parish was formed in 1807. St. Bernard Parish is part of the New Orleans–Metairie metropolitan statistical area. The parish is located southeast of New Orleans and comprises the Chandeleur Islands and Chandeleur Sound in the east. St. Bernard was the fastest growing parish in Louisiana from 2010 to 2020, increasing from a population of 35,897 in the 2010 census to 43,764 in 2020. It remains at less than two-thirds of its 2000 population of 67,229, prior to Hurricane Katrina.

Mobile ( moh-BEEL, French: [mɔbil] (listen)) is the county seat of Mobile County, Alabama, United States. The population within the city limits was 195,111 as of the 2010 United States Census, making it the third-most-populous city in Alabama, and the most populous in Mobile County. Alabama's only saltwater port, Mobile is located on the Mobile River at the head of the Mobile Bay and the north-central Gulf Coast. The Port of Mobile has always played a key role in the economic health of the city, beginning with the settlement as an important trading center between the French colonists and Native Americans, down to its current role as the 12th-largest port in the United States.Mobile is the principal municipality of the Mobile metropolitan area. This region of 412,992 residents is composed solely of Mobile County; it is the third-largest metropolitan statistical area in the state. Mobile is the largest city in the Mobile-Daphne−Fairhope CSA, with a total population of 604,726, the second largest in the state. As of 2011, the population within a 60-mile (100 km) radius of Mobile is 1,262,907.Mobile was founded in 1702 by the French as the first capital of Louisiana. During its first 100 years, Mobile was a colony of France, then Britain, and lastly Spain. Mobile became a part of the United States in 1813, with the annexation by President James Madison of West Florida from Spain. The city surrendered to Federal forces on April 12, 1865, after Union victories at two forts protecting the city. This, along with the news of Johnston's surrender negotiations with Sherman, led Taylor to seek a meeting with his Union counterpart, Maj. Gen. Edward R. S. Canby. The two generals met several miles north of Mobile on May 2. After agreeing to a 48-hour truce, the generals enjoyed an al fresco luncheon of food, drink, and lively music. Canby offered Taylor the same terms agreed upon between Lee and Grant. Taylor accepted the terms and surrendered his command on May 4 at Citronelle, Alabama.Considered one of the Gulf Coast's cultural centers, Mobile has several art museums, a symphony orchestra, professional opera, professional ballet company, and a large concentration of historic architecture. Mobile is known for having the oldest organized Carnival or Mardi Gras celebrations in the United States. Its French Catholic colonial settlers celebrated this festival from the first decade of the 18th century. Beginning in 1830, Mobile was host to the first formally organized Carnival mystic society to celebrate with a parade in the United States. (In New Orleans, such a group is called a krewe.)