‘Manchesterism’ was an epithet applied in Germany to those who subscribed to a political-economic philosophy of ‘Laissez-faire‘. It was applied, in particular, to the movement in England from 1820 to 1850 which was inspired by the propaganda of the Anti-Corn Law League. This was headed by Cobden and Bright, and supported by the economics of David Ricardo. The ‘school’ believed in free trade and political and economic freedom with the minimum of government restraint.
Reference: The Penguin Dictionary of Economics, 3rd edt.