Question: How many parts did the Louisiana territory encompass of?
About the article "Louisiana Purchase", section "Abstract".

Candidate passages:
In the USA, many of the states were territories or parts of territories before reaching statehood, e.g.
Louisiana Territory, Oregon Territory, Alaska Territory.
Immediately before reaching statehood, these territories of the United States were formally usually of a kind which can be described as organized incorporated territories. 
"Note: from 1804 to 1812, what would later become the State of Louisiana was known as the "Territory of Orleans".
The contemporary "Louisiana Territory" was to the north, and did not include modern Louisiana."
 Territorial evolution of the United States *Territory of France that encompassed land that would later become part of the Territory of Michigan: **Louisiane, 1682–1764 and 1803 *Territory of Spain that encompassed land that would later become part of the Territory of Michigan: **Luisiana, 1764–1803 *U.S. territories that encompassed land that would later become part of the Territory of Michigan: **Territory Northwest of the River Ohio, 1787–1803 **Territory of Indiana, 1800–1816 **Louisiana Purchase, 1803–1804 **District of Louisiana, 1804–1805 **Territory of Louisiana, 1805–1812 **Territory of Illinois, 1809–1818 **Territory of Missouri, 1812–1821 *U.S. territories that encompassed land that was previously part of the Territory of Michigan: **Territory of Wisconsin, 1836–1848 **Territory of Iowa, 1838–1846 **Territory of Minnesota, 1849–1858 **Territory of Dakota, 1861–1889 *U.S. states that encompass land that was once part of the Territory of Michigan: **State of Michigan, 1837 **State of Iowa, 1846 **State of Wisconsin, 1848 **State of Minnesota, 1858 **State of North Dakota, 1889 **State of South Dakota, 1889  
Under the secret Third Treaty of San Ildefonso of October 1, 1800, Louisiana and an undefined portion of West Florida were formally transferred back to France, although the Spanish continued to administer it.
The terms of the treaty did not specify the boundaries of the territory being returned.
When France then sold the Louisiana Territory to the US in 1803, a dispute arose again between Spain and the US on which parts of West Florida exactly had Spain ceded to France, which would in turn decide which parts of West Florida were now US property versus Spanish property. 
With the Louisiana Purchase in 1803, the United States acquired France’s 828,000 square mile claim to the watersheds of the Mississippi River (west of the river) and Missouri River.
The purchase encompassed all or part of 15 current U.S. states and parts of two Canadian provinces.
Out of the Louisiana Purchase, Louisiana Territory and Orleans Territory were organized.
Orleans Territory became the state of Louisiana in 1812, and Louisiana Territory was renamed Missouri Territory to avoid confusion.
Arkansas Territory was created out of the southern part of Missouri Territory in 1819.
Originally the western border of Missouri was intended to go due south to the Red River (Mississippi River).
However, during negotiations with the Choctaw in 1820, Andrew Jackson ceded more of Arkansas Territory to the Choctaw than he realized, resulting in a bend in the border between Arkansas and Oklahoma at Ft. Smith, Arkansas.