   thumb|right|280px|~ mississippi territory ~ issue of 1948 the territory of mississippi was an organized incorporated territory of the united states that existed from april 7, 1798, until december 10, 1817, when the final extent of the territory was admitted to the union as the state of mississippi. the mississippi territory was expanded in 1804 and again in 1812 until it extended from the gulf of mexico to the southern border of tennessee. (georgia gave up the northern portion in 1802, and the gulf coast region was acquired from spain.) originally mississippi territory included what is now alabama, and 9 months before mississippi was admitted into the union in 1817, the alabama territory to the east was separated out on march 3. "timeline 1811â1820" (events +sources), algis ratnikas, timelines of history, 2007, webpage: tl-miss. on december 10, 1817, mississippi was admitted to the union as the 20th state. the mississippi territory was organized in 1798 from land that had been disputed by the u.s. and spain until spain ceded its claim with the treaty of madrid initially signed between the two countries' representatives in 1795. this area extended from 31Â° n latitude to 32Â°28' north, or approximately the southern half of the present states of [[alabama
States_and_territories_established_in_1798