Question: When did the state where Pocahontas Mounds is located become part of the United States?

full_context: Document 1: Mound Bottom: Mound Bottom is a prehistoric Native American complex in Cheatham County, Tennessee, located in the Southeastern United States. The complex, which consists of earthen platform and burial mounds, a 7-acre central plaza, and habitation areas, was occupied between approximately 1000 and 1300 AD, during the Mississippian period.
Document 2: Indiana: In order to decrease the threat of Indian raids following the Battle of Tippecanoe, Corydon, a town in the far southern part of Indiana, was named the second capital of the Indiana Territory in May 1813. Two years later, a petition for statehood was approved by the territorial general assembly and sent to Congress. An Enabling Act was passed to provide an election of delegates to write a constitution for Indiana. On June 10, 1816, delegates assembled at Corydon to write the constitution, which was completed in 19 days. President James Madison approved Indiana's admission into the union as the nineteenth state on December 11, 1816. In 1825, the state capital was moved from Corydon to Indianapolis.
Document 3: History of Mississippi: In 1817 elected delegates wrote a constitution and applied to Congress for statehood. On Dec. 10, 1817, the western portion of Mississippi Territory became the State of Mississippi, the 20th state of the Union. Natchez, long established as a major river port, was the first state capital. As more population came into the state and future growth was anticipated, in 1822 the capital was moved to the more central location of Jackson.
Document 4: Mississippi: In April 1699, French colonists established the first European settlement at Fort Maurepas (also known as Old Biloxi), built in the vicinity of present - day Ocean Springs on the Gulf Coast. It was settled by Pierre Le Moyne d'Iberville. In 1716, the French founded Natchez on the Mississippi River (as Fort Rosalie); it became the dominant town and trading post of the area. The French called the greater territory ``New France ''; the Spanish continued to claim part of the Gulf coast area (east of Mobile Bay) of present - day southern Alabama, in addition to the entire area of present - day Florida.
Document 5: Minnesota: In 1762 the region became part of Spanish Louisiana until 1802. The portion of the state east of the Mississippi River became part of the United States at the end of the American Revolutionary War, when the Second Treaty of Paris was signed. Land west of the Mississippi River was acquired with the Louisiana Purchase, although a portion of the Red River Valley was disputed until the Treaty of 1818. By the late 1700s, the North West Company had established the post of Fort Charlotte at the Lake Superior end of the Grand Portage, until moving 50 miles northeast to Fort William in 1803. In 1805, Zebulon Pike bargained with Native Americans to acquire land at the confluence of the Minnesota and Mississippi rivers. The construction of Fort Snelling followed between 1819 and 1825. Its soldiers built a grist mill and a sawmill at Saint Anthony Falls, the first of the water-powered industries around which the city of Minneapolis later grew. Meanwhile, squatters, government officials, and tourists had settled near the fort. In 1839, the army forced them to move downriver and they settled in the area that became St. Paul. Minnesota Territory was formed on March 3, 1849. The first territorial legislature (held September 2, 1849) was dominated by men from New England or of New England ancestry. Thousands of people had come to build farms and cut timber, and Minnesota became the 32nd U.S. state on May 11, 1858. The founding population was so overwhelmingly of New England origins that the state was dubbed "the New England of the West".
Document 6: Mississippi House of Representatives: The Mississippi House of Representatives is the lower house of the Mississippi Legislature, the lawmaking body of the US state of Mississippi. According to the state constitution of 1890, it is to comprise no more than 122 members elected for four-year terms. To qualify as a member of the house candidates must be at least 21 years old, a resident of Mississippi for at least four years, and a resident in the district in which he or she is running for at least two years. Current state law provides for the maximum number of members. Elections are held the first Tuesday after the first Monday in November.
Document 7: Indian Mounds Park (Saint Paul, Minnesota): Indian Mounds Regional Park is a public park in Saint Paul, Minnesota, United States, featuring six prehistoric Native American burial mounds overlooking the Mississippi River. The oldest mounds were constructed 1,500 -- 2,000 years ago by people of the Hopewell tradition. Later the Dakota people interred their dead there as well. At least 31 more mounds were destroyed by development in the late 19th century. They were the tallest Native American mounds in Minnesota or Wisconsin (except for the unique 45 - foot (14 m) Grand Mound outside International Falls, Minnesota), and comprise one of the northwesternmost Hopewellian sites in North America. Indian Mounds Regional Park is a component of the Mississippi National River and Recreation Area, a unit of the National Park System. The Mounds Group is listed on the National Register of Historic Places. The 2014 nomination document provides a description of the archaeology and the context.
Document 8: Mississippi: Mississippi ( (listen)) is a state located in the southeastern region of the United States. Mississippi is the 32nd largest and 34th-most populous of the 50 United States. Mississippi is bordered to north by Tennessee, to the east by Alabama, to the south by the Gulf of Mexico, to the southwest by Louisiana, and to the northwest by Arkansas.  Mississippi's western boundary is largely defined by the Mississippi River.  Jackson is both the state's capital and largest city.  Greater Jackson, with an estimated population of 580,166 in 2018, is the most populous metropolitan area in Mississippi and the 95th-most populous in the United States.
Document 9: National Register of Historic Places listings in Hinds County, Mississippi: This is intended to be a complete list of the properties and districts on the National Register of Historic Places in Hinds County, Mississippi, United States. Latitude and longitude coordinates are provided for many National Register properties and districts; these locations may be seen together in a map.
Document 10: Constitution of Florida: Florida's first constitution as a U.S. territory was written and implemented in 1838. On March 3, 1845, Florida was granted admission into the Union as the 27th state. The current Constitution of Florida was ratified on November 5, 1968, and has been modified by initiative and referendum several times since.
Document 11: Constitution of Missouri: The first constitution was written in 1820 in only 38 days. The Missouri Constitutional Convention (1861 - 63) was elected to decide on secession, and made no changes to the constitution.
Document 12: Nacoochee Mound: The Nacoochee Mound (Smithsonian trinomial 9WH3) is an archaeological site on the banks of the Chattahoochee River in White County, in the northeast part of the U.S. state of Georgia, at the junction of Georgia State Route 17 and Georgia State Route 75. First occupied as early as 100-500 CE, the site was later developed and occupied more intensively by peoples of the South Appalachian Mississippian culture (a regional variation of the Mississippian culture) from 1350 to 1600 CE. One of their characteristic platform mounds is located at the site. A professional archeological excavation revealed a total of 75 human burials, with artifacts that support dating of the site.
Document 13: North Carolina: North Carolina was inhabited for thousands of years by succeeding cultures of prehistoric indigenous cultures. Before 200 AD, they were building earthwork mounds, which were used for ceremonial and religious purposes. Succeeding peoples, including those of the ancient Mississippian culture established by 1000 AD in the Piedmont, continued to build or add on to such mounds. In the 500–700 years preceding European contact, the Mississippian culture built large, complex cities and maintained far-flung regional trading networks. Its largest city was Cahokia, located in present-day Illinois near the Mississippi River.
Document 14: Arledge Mounds I and II: Most unusual is the proximity of the mounds to each other — while many groups of mounds are known in Ohio, they are not typically connected at the base as these two mounds are; only the Arledge Mounds and the McMurray Mounds, which straddled the border between Franklin and Madison counties, are known to have been conjoined. Although these mounds have not been excavated, archaeologists have proposed that they were built by the Adena culture, who are known to have built the McMurray Mounds.
Document 15: Pocahontas Mounds: Pocahontas Mounds (22 HI 500) is an archaeological site from the Plaquemine Mississippian culture in Hinds County, Mississippi, dating from 800 to 1300 CE. Two mounds from the site were added to the NRHP on two separate occasions, "Pocahontas Mound A" on November 25, 1969 as NRIS number 69000365 and "Pocahontas Mound B" on April 11, 1972 as NRIS number 72000694.
ground_truth: Dec. 10, 1817
sub_queries: Which state is Pocahontas Mounds located? Answer: Mississippi
when did Mississippi become part of the united states Answer: Dec. 10, 1817