Indiana Territory separated from Northwest Territory
The Indiana Territory, officially the Territory of Indiana, was created by an organic act that President John Adams signed into law on May 7, 1800, to form an organized incorporated territory of the United States that existed from July 4, 1800, to December 11, 1816, when the remaining southeastern portion of the territory was admitted to the Union as the state of Indiana. The territory originally contained approximately 259,824 square miles (672,940 km2) of land, but its size was decreased when it was subdivided to create the Michigan Territory (1805) and the Illinois Territory (1809). The Indiana Territory was the first new territory created from lands of the Northwest Territory, which had been organized under the terms of the Northwest Ordinance of 1787. The territorial capital was the settlement around the old French fort of Vincennes on the Wabash River, until transferred to Corydon near the Ohio River in 1813.
William Henry Harrison, the territory's first governor, oversaw treaty negotiations with the Native inhabitants that ceded tribal lands to the U.S. government, opening large parts of the territory to further settlement. In 1809 the U.S. Congress established a bicameral legislative body for the territory that included a popularly-elected House of Representatives and a Legislative Council. In addition, the territorial government began planning for a basic transportation network and education system, but efforts to attain statehood for the territory were delayed due to war. At the outbreak of Tecumseh's War, when the territory was on the front line of battle, Harrison led a military force in the opening hostilities at the Battle of Tippecanoe (1811) and in the subsequent invasion of Canada during the War of 1812. After Harrison resigned as the territorial governor, Thomas Posey was appointed to the vacant governorship, but the opposition party, led by Congressman Jonathan Jennings, dominated territorial affairs in its final years and began pressing for statehood.
In June 1816 a constitutional convention was held at Corydon, where a state constitution was adopted on June 29, 1816. General elections were held in August to fill offices for the new state government, the new officeholders were sworn into office in November, and the territory was dissolved. On December 11, 1816, President James Madison signed the congressional act that formally admitted Indiana to the Union as the nineteenth state.Geographical boundaries
When the Indiana Territory was formed in 1800, its original boundaries included the western portion of the Northwest Territory. This encompassed an area northwest of a line beginning at the Ohio River, on the bank opposite the mouth of the Kentucky River, extending northeast to Fort Recovery in present-day western Ohio, and north to the border between the United States and Canada along a line approximately 84 degrees 45 minutes West longitude.The territory initially included most of the present-day state of Indiana; all of present-day states of Illinois and Wisconsin; fragments of present-day Minnesota that were east of the Mississippi River; nearly all of the Upper Peninsula and the western half of the Lower Peninsula of present-day Michigan; and a narrow strip of land in present-day Ohio that was northwest of Fort Recovery. This latter parcel became part of Ohio when it attained statehood in 1803. The Indiana Territory's southeast boundary was shifted in 1803 when Ohio became a state, to the mouth of the Great Miami River. In addition, the eastern part of present-day Michigan was added to the Indiana Territory. The territory's geographical area was further reduced in 1805 with the creation of the Michigan Territory to the north, and in 1809 when the Illinois Territory was established to the west.History
The area that became the Indiana Territory was once part of the Northwest Territory, which the Congress of the Confederation formed under the terms of the Northwest Ordinance on July 13, 1787. This ordinance outlined the basis for government in the western lands and also provided for an administrative structure to oversee the territory, including a three-stage process for transitioning from territory to statehood. In addition, the Land Ordinance of 1785 called for the U.S. government to survey the newly-acquired territory for future sale and development. The Northwest Territory, which initially included land bounded by the Appalachian Mountains, Mississippi River, Great Lakes, and Ohio River, was subsequently partitioned into smaller territories that included the Indiana Territory (1800), Michigan Territory (1805), the Illinois Territory (1809), and eventually became the present-day states of Ohio, Michigan, Indiana, Illinois, Wisconsin, and eastern Minnesota.