In 1804, all of the Louisiana Purchase south of the 33rd parallel became the Orleans Territory, and the remainder became the District of Louisiana. The Organic Act of 1804, passed on March 26 for October 1 implementation, also created the United States District Court for the District of Orleans—the only time Congress has ever provided a territory with a United States district court equal in its authority and jurisdiction to those of the states. Congress also established the Superior Court for the Territory of Orleans whose three judges were the top territorial court. On April 10, 1805, the Territorial Legislature organized 12 counties : Orleans County, LaFourche County, German Coast, Acadia County, Iberville County, Attakapas County, Pointe Coupée County, Opelousas County, Rapides County, Concordia County, Natchitoches County, and Ouachita County. The Florida Parishes on the east side of the Mississippi River were not included in Orleans Territory at this time, as they were in the Spanish territory of West Florida until they were formally annexed on April 14, 1812. The western boundary with Spanish Texas was not fully defined until the Adams-Onís Treaty in 1819. A strip of land known as the Sabine Free State just east of the Sabine River served as a neutral ground buffer area from about 1807 until 1819. The Orleans Territory was the site of the largest slave revolt in American history, the 1811 German Coast Uprising.

Based on the above article, answer a question. For how many years after the creation of the Orleans Territory did the Florida parishes east of the Mississippi remain part of the Spanish territory of West Florida?
8