Named for: Indian Chief Tamanend

In 1699, Pierre Le Moyne d'Iberville, a French explorer, became the first European to visit the area of present-day St. Tammany Parish. While exploring lakes Pontchartrain and Maurepas, Iberville wrote in his journal, "The place where I am is one of the prettiest I have seen, fine level ground bare of canes. The land north of the lakes is a country of pine trees mixed with hard woods. The soil is sandy and many tracks of buffalo and deer can be seen."

St. Tammany was originally inhabited by numerous Indian peoples, including the Colapissas, Bayou Goulas, Chickasaw, Biloxi, Choctaw, and Pensacola nations (although, Frederick S. Ellis, in his book St. Tammany Parish: L’autre Côté du Lac, claims that the regionally prominent Choctaw tribe did not arrive to the area until after it had begun to be settled by Europeans).

After the founding and development of New Orleans, French settlers began to enter the region. Their primary industry was the production of pitch, tar, turpentine and resin from the forests.

After the French were defeated in the French and Indian War, St. Tammany (like the surrounding regions of the Florida Parishes) became part of English West Florida. Then, after Britain was defeated in the American Revolutionary War, West Florida was governed by the Spanish. During the West Florida period, St. Tammany, like the rest of West Florida, attracted British loyalists who wanted to escape persecution in the 13 colonies. The West Florida period ended with the West Florida Revolt, which preceded West Florida's annexation by the United States.

In 1810, President James Madison claimed West Florida as part of Louisiana and sent William C.C. Claiborne to claim the territory. Claiborne established the boundaries of the Florida Parishes, including St. Tammany. St. Tammany was named after Indian Chief Tamanend.[2]

Before 1834, there were only two towns in St. Tammany: Covington, a retreat with summer homes and hotels; and Madisonville, a shipbuilding and sawmill town. The area south to Lake Ponchartrain all the way to the Pearl River were known as the Covington Lowlands, this includes Mandeville, Abita Springs, Lacombe, Slidell, and Pearl River. Mandeville was developed that year as a health resort for wealthy New Orleanians, because they believed that Ozone was emitted from the numerous trees in the area and became an immediate success, spurring the development of another resort community, Abita Springs. A railroad connected the towns to Mandeville and further to New Orleans, allowing for a burgeoning of growth in Abita Springs, where underground spring waters furnished supposedly healthful baths for public use.

After the construction of the Lake Pontchartrain Causeway, Interstate 12 and Interstate 10, people began to relocate to St. Tammany in large numbers.

While the economy of the Greater New Orleans Metro area began to have several major problems,(very high taxes on the middle class) the middle and upper classes began to move further and further from New Orleans, eventually moving across Lake Pontchartrain to the then mostly rural St. Tammany. Population and economic growth accelerated after 1956, when the first span of the Lake Ponchartrain Causeway bridge was completed. The population exceeded 200,000 in the wake of Hurricane Katrina's landfall in 2005.

~ Municipalities ~

Cities
- Covington
- Mandeville
- Slidell

Towns
- Abita Springs
- Madisonville (Information by Wikipedia)
- Pearl River (Information by Wikipedia)

Villages
- Folsom (Information by Wikipedia)
- Sun (Information by Wikipedia)

Census-designated places
- Eden Isle (Information by Wikipedia)
- Lacombe (Information by Wikipedia)

Unincorporated places
Alton
Amos
Audubon
Big Branch
Blond
Bonfouca
Bush (Information by Wikipedia)
Chinchuba
Crawford
Landing
Dave
Davis Landing
Florenville
Goodbee
Haaswood
Houltonville
Hickory
Lewisburg
Maude
McClane City
Morgan Bluff
North Slidell
Oaklawn
St. Benedict
St. Joe
St. Tammany
St. Tammany Corner
Talisheek
Waldheim
White Kitchen