Construction of a railroad south from St. Louis to the iron and lead mining areas of Missouri was a project of prime importance during the early 1850's. Following determination of a route by government surveyors, the St. Louis and Iron Mountain Railroad was established in 1852. Author ization of state aid was obtained and by July, 1853, the government surveyed route along the river through Carondelet was adopted. Delays were encountered in negotiations with Army authorities for routing through the St. Louis Arsenal Grounds and Jefferson Barracks. Construction began in stages and in 1855, track was laid between the Arsenal and Carondelet.
In 1856, service began with an "omnibus train" so called because passengers from St. Louis were required to take a horse drawn omnibus to reach the temporary railroad station at Lami Street before proceeding to Carondelet Two years later, the line was completed and full service was initiated. The vicinity of Carondelet was served by railroad stations at Elwood Street, Krauss Street, Robert Avenue and at the dry docks (Davis Street). The scheduled time from Elwood to Plum Street in St. Louis was forty minutes. In 1859, extensive railroad machine shops were built in Carondelet, employing more than 500 persons. The line was heavily used for both commuters and freight hauling especially iron ore to Carondelet's works.
A branch line, with a station at Ivory and Alabama, was built to Kirkwood and another division called the Oak Hill branch was opened in 1887. The Kirkwood branch was used as a by-pass for freight trains destined for the eastern states, leading to establishment of a railroad ferry at the foot of Steins Street. Passenger stations were built on this line at Broadway and on the Oak Hill branch in Carondelet Park near Loughborough Avenue. The former was razed in 1972, after being a local landmark for many years. In 1917, the Iron Mountain line was absorbed by the Missouri Pacific System. As a side light, the Missouri Pacific hospital had its beginning about 1880, as a facility for Iron Mountain employees, in the old Blow mansion at Virginia, Haven and Loughborough Avenues.
Earliest form of public transit between Carondelet and St. Louis was a horse drawn omnibus during the late 1840's. Better omnibuses were used during the fifties but the first horse car line did not begin operations until January, 1860. It ran on Broadway and Michigan and Virginia Avenues. It failed because it emcompassed too great of an area for the number of riders it attracted. At that time the much faster railroad was used for passengers going to St. Louis. Another line of horsecars was inaugurated in May, 1875. It operated on Broadway from Davis Street to Meramec Street where connections were made with a line into St. Louis.
Tracks were also laid on Michigan and Virginia Avenues with connections to Broadway at Elwood and at Davis Street. The latter portion was later abandoned. The line operated twenty cars every ten or fifteen minutes on a single track with intermittent passing switches. Motive power was provided by a single mule pulling each car. Electrification of the street car lines began in 1891 when the Broadway line was converted and by 1894, service was restored to the long abandoned Virginia Avenue sector south of Meramec Street. This was done by extending the California Avenue (later Bellefontaine) line southward to its terminus at Primm Street. Electric street cars served the Carondelet area until the 1950's when motor busses were substituted. Competition from local transit eventually caused a cessation of the commuter rail service on the Iron Mountain railroad along the river and on the Oak Hill branch.
Originally, Carondelet was populated by French and Creole settlers until the immigration of Germans began after 1840. Soon after the Germans, a tide of Irish arrived in the town and after the Civil War, many negroes came up-river as deck hands and roustabouts on steamboats. Many of them remained in Carondelet to work as laborers at the blast furnaces and foundries. American residents from St. Louis and the east and south began to settle in Carondelet before 1850, giving the community a diverse population. The last major group to come to Carondelet were the Spanish who arrived between 1910 and 1915, to work in local zinc pIants. Since 1960, the area has experienced about a 20% decline in population due to highway conatruction and demolition.