War with France began again in 1778, and once more it was necessary to strengthen the defences. Fort Amherst was the first to be improved; it was followed by work beginning in 1800 to add others at Fort Pitt, Chatham, plus Fort Delce and Fort Clarence (both in Rochester); later in the 19th century others were added, including one at Fort Darland in Gillingham. Within all these buildings a barracks was built to house the soldiers. All this work, and the expansion of the dockyard, meant that more homes were needed for the workers. The position of the Lines meant that this building could only happen beyond, and so New Brompton came into being. The population rose to 9,000 people by 1851.