Centrally located, Missouri is the leading US transportation center. Both St. Louis and Kansas City are hubs of rail, truck, and airline transportation.
In 1836, delegates from 11 counties met in St. Louis to recommend construction of two railroad lines and to petition Congress for a grant of 800,000 acres (324,000 hectares) of public land on which to build them. More than a dozen companies were incorporated by the legislature, but they all collapsed with the financial panic of 1837. Interest in railroad construction revived during the following decade, and in 1849 a national railroad convention was held in St. Louis at which nearly 1,000 delegates from 13 states recommended the construction of a transcontinental railroad. By 1851, three railroad lines had been chartered, and construction by the Pacific Railroad at St. Louis was under way; the Pacific line reached Kansas City in 1865, and a bridge built over the Missouri River four years later enabled Kansas City to link up with the Hannibal and St. Joseph Railroad, providing a freight route to Chicago that did not pass through St. Louis. In 2000, there were 4,541 rail mi (7,308 km) of track in the state, including 3,616 rail mi (5,819 km) of Class I track. In 1996, Amtrak provided eight passenger trains running directly from Chicago to St. Louis and to Kansas City, en route to San Antonio and Los Angeles, and two daily Kansas City–St. Louis round trips. Amtrak trains made eight other Missouri stops between St. Louis and Kansas City.
The first road developed in colonial Missouri was probably a trail between the lead mines and Ste. Genevieve in the early 1700s. A two-level cantilever bridge—the first in the world to have a steel superstructure—spanning the Mississippi at St. Louis was dedicated on 4 July 1874. By 1940, no place in Missouri was more than 10 mi (16 km) from a highway. In 2000, there were 123,039 mi (198,012 km) of public roads in Missouri. The main interstate highways were I-70, linking St. Louis with Kansas City; I-44, connecting St. Louis with Springfield and Joplin; I-55, linking St. Louis with Chicago, Illinois, to the north and paralleling the course of the Mississippi between St. Louis and Memphis, Tennessee; I-35, connecting Kansas City with Des Moines, Iowa; and I-29, paralleling the Missouri River north of Kansas City. Motor vehicle registration for the state in 2000 was 4,640,569, including 2,715,215 passenger cars, 1,851,429 trucks, and 12,985 buses; 3,856,271 driver's licenses were in force during the same year.
The Mississippi and Missouri rivers have long been important transportation routes. Pirogues, keelboats, and flatboats plied these waterways for more than a century before the first steamboat, the New Orleans, traveled down the Mississippi in 1811. The Mississippi still serves considerable barge traffic, making metropolitan St. Louis an active inland port area, with 33.3 million tons of cargo handled in 2000.
Pioneering aviators in Missouri organized the first international balloon races in 1907 and the first US-sponsored international aviation meet in 1910. Five St. Louis pilots made up the earliest US Army air corps, and a barnstorming pilot named Charles A. Lindbergh, having spent a few years in the St. Louis area, had the backing of businessmen from that city when he flew his Spirit of St. Louis across the Atlantic in 1927. Today, Kansas City International Airport and Lambert-St. Louis Municipal Airport are among the busiest airports in the country.