In the early 18th century, the military roads were constructed (on occasion at gunpoint in the face of opposition from landowners) by the governor, General George Don, to link coastal fortifications with St. Helier harbour. These had an unexpected effect on agriculture once peace restored reliable trade links. Farmers in previously isolated valleys were able to swiftly transport crops grown in the island's microclimate to waiting ships and then on to the markets of London and Paris ahead of the competition. In conjunction with the later introduction of steamships and the development of the French and British railway systems, Jersey's agriculture was no longer as isolated as before.