St. Louis was the city of next importance on the Mississippi. Until after 1855, St. Louis remained strictly a river city, almost entirely dependent upon the Mississippi and its tributaries for both the importation and exportation of the flour, grain, meat, tobacco, lead and other goods that entered and left its busy markets. After the city secured railway connection with the East in 1855 a large part of the traffic entering from that direction was transferred to the railroads, and some of the traffic leaving the city was diverted from the southern river route to the eastern railway route. However, the volume of trade taken from the Mississippi was not large at first and the movement of commodities southward showed no marked decline until the outbreak of the Civil War. Next to the river trade, the trade in live stock and slaves was the most important element in the internal commerce between the North and the South. Each year large droves of horses, mules, cattle and hogs were driven into the South from the Northern and "border" states, the farmers all over the corn-raising section finding an unfailing source of gain in the demand for live stock in the southern cotton fields. The domestic slave trade commenced to be of importance after 1820, when cotton culture spread among the Gulf States. Slaves were bought in South Carolina, Georgia, Alabama, Mississippi, Louisiana, Arkansas and Texas, and exported from Virginia, Maryland, North Carolina, Kentucky, Tennessee, Missouri and Delaware. Though no statistics of the volume of the internal slave trade exist, evidence from contemporary accounts indicates that it was unquestionably extensive, probably reaching a value of $30,000,000 a year in the late fifties. 3. TRADE OF THE FAR WEST Long before Texas and the California territory became a part of the United States, enterprising merchants on the western frontier began a merchandise trade with the Mexican settlements in what is now New Mexico. By 1843 this trade reached an annual value of $500,000. After the occupation of the territory by the United States troops it became much larger, reaching a total value in 1860 of $3,800,000. The chief shipping points were Independence and Kansas City, Missouri. Transportation was supplied by regular freighters who employed a large number of men to conduct the white-topped prairie schooners across the unsettled plains between the Missouri River and the mountains. New Mexico paid for its imports with bullion and wool produced in the territory, or with money secured by the sale of sheep driven to California, or by the sale of a scanty agricultural produce to government military posts and Indian agencies.