The dramatic expansion of the railroad network in the 1850s, however, strained the financing capacity of local governments and required a turn toward private investment, which had never been absent from the picture. Well aware of the economic benefits of railroads, individuals living near them had long purchased railroad stock issued by governments and had directly bought stock in railroads, often paying by contributing their labor to building the railroads. But the large railroads of the 1850s needed more capital than such small investors could generate. Gradually, the center of railroad financing shifted to New York City, and in fact, it was the railroad boom of the 1850s that helped make Wall Street in New York City the nation's greatest capital market. The stocks of all the leading railroads were traded on the floor of the New York Stock Exchange during the 1850s. In addition, the growth of railroads turned New York City into the center of modern investment firms. The investment firms evaluated the stock of railroads in the smaller American cities and then found purchasers for these stocks in New York City, Philadelphia, Paris, London, Amsterdam, and Hamburg. Controlling the flow of funds to railroads, the investment bankers began to exert influence over the railroads' internal affairs by supervising administrative reorganizations in times of trouble.
