Arkan'sas (formerly pron. Ar'kansaw), a state of the American Union, is bounded on the N. by Missouri, on the E. by Missouri, Tennessee, and Mississippi, on the S. by Louisiana, and on the W. by Texas and the Indian Territory. Area, 53,850 sq. m. - about that of England without Wales, of which some 800 sq. m. is water-surface. The southern limit is the parallel of 30° N. lat., and the northern boundary for the most part is on the parallel of 36° 30'. The Mississippi River washes nearly all the eastern border of the state. The extreme east and west limits are respectively 89° 40' and 94° 42' W. long. Nearly all the country is well timbered. Along the eastern border of the state lies a strip of rich alluvial and swampy land, limited westward by Crowley's Ridge. A similar low and wet tract is traversed by the lower Arkansas River. The southern half of the state contains great areas of yellow and loamy land of Tertiary age, interspersed thinly with tracts of red clays and hills of iron-ore. West of the Crowley's Ridge region is a considerable breadth of gray silty prairies. In the west of the yellow Tertiary loams are large patches of 'black prairie' of Cretaceous age. The west and central portions of the state form a broken hill-region of Tertiary origin. Great prairies of red loam and clay soil prevail in the W. and NW. Towards the north is the Ozark mountain-region, a broken country of high hills and ridges. The soils, though of extremely various character, are mostly good throughout the state. The coal-measures very extensively underlie the surface, and coal crops out at many points; but thus far it has not been much wrought. Silver-bearing galena and zinc appear to be abundant, and iron-ores exist in vast amounts. The villages of Hot Springs in Garland county, and Eureka Springs in the NW., are celebrated health-resorts. The novaculite, or hone-stone, of this state is extensively wrought and exported. The Mississippi, Arkansas, Red, White, St Francis, Ouachita, and other navigable rivers afford cheap transport. Agriculture is the leading pursuit in Arkansas, and cotton is the great staple of production. Maize is also very largely produced, and considerable quantities of oats and wheat are harvested. Live-stock, wool, tobacco, pork, fruit, and dairy products are marketed. Although malarial fevers and severe heat are to be encountered in the marshy and flat alluvial districts, the larger portion of the country has an agreeable and healthful climate. In quality, variety, and accessibility, the timber of this state is hardly surpassed. The mineral resources of the state have been but little utilised. Lying outside the great currents of immigration, Arkansas has, until very recent years, preserved to a remarkable degree the character of a frontier country. Even the large extent of river navigation for a long time served to hinder the development of the country, since it discouraged the construction of railways; and the old system of slave labour and of large holdings of land was not favourable to rapid material development. This region formed a part of the French colony of Louisiana, and was purchased, together with the rest of that colony, by the United States in 1803. The earliest French settlement was made at Arkansas Post in 1685. Arkansas was organised as a territory in 1819, and became a state in 1836, and seceded in 1861.

The principal towns are Little Rock, the state capital (pop. 40,000), Pine Bluff (12,000), and Fort Smith (11,000); Hot Springs (9500) is a health-resort. Pop. of Arkansas (1820) 14,255; (1860) 435,450; (18S0) 802,525; (1890) 1,128,179; (1900) 1,311,564, of whom upwards of 366,000 were of African or mixed descent.