LOUISIANA, a city of Pike county, Missouri, U.S.A., situated below the mouth of the Salt river, on the western bank of the Mississippi, about 90 m. N. of St. Louis. Pop. (1900) 5131, including 1075 negroes and 161 foreign-born; (1910) 4454; there is also a considerable suburban population. Louisiana is served by the Chicago, Burlington & Quincy and the Chicago & Alton railways, and by several lines of river steamboats. The river is spanned here by a railway bridge. The city is laid out fairly regularly in the river valley and on bluffs along the river, and has attractive residential districts, commanding good views. It has very active and varied industries, and is a trade centre for a large grain- and fruit-producing and stock-raising region, and has one of the largest nurseries in the United States. Louisiana was laid out in 1818, was the county-seat from that date until 1825, was incorporated as a town in 1845 and was chartered as a city in 1849. LOUISIANA PURCHASE, a large portion of the area of the United States of America, purchased from the French Republic in 1803. The territory to which France held explorer's title originally included the entire valley of the Mississippi (see Louisiana); but the "Louisiana" which was ceded by her to Spain in 1762 (England refusing it, preferring the Floridas), retroceded to France in 1800,[1] and ceded by Napoleon to the United States--in violation of his pledge to Spain that he would not alienate the province--embraced only the portion W. of the river and the island of New Orleans on the E. (and, as might be claimed with some show of argument, West Florida to the Perdido river).