Within the walls of Destrehan Plantation, there is a climate controlled room displaying an original document signed by Thomas Jefferson. The document dated 1804, assigns four men, one of whom is Jean Noel Destrehan, to the Orleans Territorial Council. This document is considered one of the most important in Louisiana history and is known as the “Jefferson Document.” Quality reproductions of other documents vital to Louisiana history are also on display in the Jefferson Room.

The men listed on the “Jefferson Document” were hand picked to form the Orleans Legislative Council. This group of respected landowners, with long histories in Louisiana, helped ease the cultural transition of the Orleans Territory into an American representative democracy. At the time of the Louisiana Purchase, the people of the Orleans Territory still considered themselves Frenchmen or Spaniards and their attitude towards the new American rule clashed with their deeply rooted traditions. The Orleans Legislative Council was vital in representing the residents of this area to the United States until Louisiana became a state in 1812. The council gave Louisianians an immediate voice in their new system of government.

One precedent established during this tenure, that continues today, is the sub-dividing of Louisiana into Parishes as opposed to counties, as in the rest of the nation.

The Louisiana Purchase has been described as the greatest real estate deal in history. In 1803 the United States paid France $15 million for the Louisiana Territory, 828,000 square miles of land west of the Mississippi River. Thirteen states were carved from the Louisiana Territory. The larger portion of the Louisiana Purchase lying north of the 33 degree latitude line (the present boundary between LA and AR) was known as the Missouri Territory. The lower portion to the south constituted the Territory of Orleans.