Rich in history and culture, the City of Opelousas is the third oldest city in Louisiana. It is a place influenced by a mixture of nationalities. From its architectural offerings to its role in the Civil War to its plentiful Cajun and Creole traditions, the city’s diverse cultures are captured in many different ways.   As a result of the Louisiana Purchase in 1803, the area was divided into two parts.   The lower part became known as the Territory of Orleans, which is now the State of Louisiana. This Territory of Orleans was divided into twelve counties, which included the County of Opelousas. In 1805, Opelousas became the seat of government for this County. A year later, the first Opelousas County Courthouse was built on a square in the center of town. Today, the area around the courthouse is designated as a National Historic District.