Shortly after the Louisiana territory was purchased by the United States, the newly created Legislative Council met in 1804 and divided the State into 12 counties. These counties were Orleans, German Coast, Acadia, LaFourche, Iberville, Pointe Coupee, Concordia, Attakapas, Opelousas, Rapides, Ouachita, and Natchitoches. These counties proved to be too large for satisfactory administration, and, in 1807, the State was divided into 19 parishes based, for the most part, on ecclesiastical (Church) parishes as established in 1769 by the Spanish provisional governor. Thus, a parish became the local government district. As a consequence, when Louisiana became a state, the term "parish" was taken over with the name of the region to which it had applied under Spanish rule. Today, after a number of revisions, Louisiana has 64 parishes.
In 1807, the Legislative Council created a form of government by designating a parish judge and a 12-member jury to serve as the governing body of each parish, with the parish judge as the top elected official. This body was charged with responsibility for "execution of whatever concerns the interior and local police and administration of the parish."
Another step was taken in 1810 when legislation created the office of Sheriff for each parish. About a year later, on April 30, 1811, the State adopted an act making jury members elective and designated this body officially as a "police jury." Powers of parish judges were reduced and made ex-officio members. Two years later, on March 25, 1813, legislation provided for wards-identified sections of a parish- to serve on the police juries. Members served without receiving pay, but were also subject to being fined if they didn’t attend meetings.
Parish judges continued to serve on police juries as ex-officio presidents until 1839, when legislation excluded them from membership. Police juries were gradually given added powers over the next two decades and began to function much as they do today.