CAIRO (ka'ro), a city in the southern tip of Illinois, U.S.A., on the Mississippi river at the mouth of the Ohio, 15om. S.E. of St. Louis; the county seat of Alexander county. It is on Federal highways 51 and 6o; and is served by the Illinois Central, the Mobile and Ohio, the Big Four, the Missouri Pacific, and the St. Louis South-western railways, by ferries across both rivers, and by the Federal barge line and other steamers on both rivers. The population in 1920 was 15,203, of whom 5,000 were negroes, and was 13,532 in 1930 by the Federal census. The city is built on a tongue of land between the rivers, protected by great levees which withstood even the flood of 1927, when the Mississippi rose to 58ft. and the Ohio to 56.4ft. Its fine situation and transportation facilities make it an important shipping and transhipping centre, not only for fertile southern Illinois (popularly called "Egypt") but for the entire Mississippi valley and far distant ports. The city's jobbing business amounts to $55,000,000 a year. There are various manufacturing industries (including flour, lumber, veneer and articles made of wood), with an output in 1925 valued at $7,210,861. At Mound City, 5m. N., is a national cemetery, con taining 5,532 graves.
After abortive attempts in 1818 and in 1835, a successful set tlement was made here in 1851-54, under the auspices of the New York Trust Company. The Illinois Central Railroad was opened in 1856, and the city was chartered in 1857. During the Civil War it was an important strategic point, and was a military centre and depot of supplies for the Federal armies in the West. At Mound City Admiral Andrew H. Foote in 1862 established a naval depot for the base of his operations on the Mississippi. Cairo is said to be the "Eden" of Charles Dickens's Martin Chuzzlewit.