Before the Railway Mania of 1845–46, large-scale financial fraud had been episodic, appearing dramatically in speculative disasters such as the South Sea Bubble of 1720 or the 1825 Commercial Crisis. With the coming of the railways, however, big business and business fraud were here to stay. Railways pioneered the joint-stock company form a half-century before it became general in most other fields. In the words of Harold Perkin, “big business on the scale we know it today began with the railways in the nineteenth century.” So too did white-collar crime.

Railways transformed English finance as surely as they changed the face of the English landscape. The London Gazette, which published all Parliamentary schemes for companies, had been, previous to 1845, a slender volume. Due to the enormous proliferation of railway companies in 1845, the Gazette swelled to over 4,000 pages. It would never be light weight again. In 1845 Parliament sanctioned 2,816 miles of new railway line, an amount equal to all the miles sanctioned between 1821 and 1843. An additional 4,540 miles were sanctioned in 1846. At its peak in 1846–47, railway expenditure absorbed almost 7% of national income.

Railways broadened the base of investment. For the first time the Stock Exchange dealt significantly with company shares instead of government bonds. The Mania of the mid-forties drew in the whole nation of investors. The aristocracy and gentry became heavily involved in railway shareholding since they were often given large blocks of shares to secure their goodwill for lines crossing their estates. At mid-century, Thomas Tooke observed: “In every street of every town persons were to be found who were holders of Railway shares.”