The prosperity of the lairds gradually increased after the Reformation. Some began to think of ways to increase it still further. In the late seventeenth century Patrick McDouall of Logan began attempts, which continued into the nineteenth century, to establish a ferry-port for Ireland at Port Nessock, later renamed Port Logan.

 He built a new quay, now no longer visible, but until the middle twentieth century still called the Wee Quay. He also built Logan Windmill to lessen the estate's dependence on waterpower, which in summer was liable to failure. In 1702 Colonel Andrew McDouall built Logan House in classical style. By 1800 Logan Fish Pond had been constructed to ensure the supply of fish to Logan House, whatever the weather.

In the early nineteenth century a second Colonel Andrew McDouall made further attempts to improve the harbour at Port Logan, building the present quay and harbour light, and also making alterations in the village to improve access and to provide accommodation for travellers and officials. The construction of the Battery, the Inn, and the High Row ('Heigh Raw') was the result. Stone for building operations was quarried at Quarry Bay and Slate Heugh. The cutting through which the stone was transported to the seaside is still visible.

In the early-nineteenth century, Chapel Rossan was built as a house for the estate factor. The main building at Balgowan may have been erected as a dower house. Later in the century, Logan Tile Works, now a ruin, was established at Terally to provide bricks and tiles for local use. Logan Saw Mill, operated by waterpower, was also developed.

The McDoualls of Logan did not confine their attention to their estate. Andrew McDouall (1685-1750), second son of Robert McDouall of Logan, wrote a major work on Scots Law, The Institute of the Laws of Scotland in Civil Rights (1751-3). In 1755 he became a judge of the Court of Session in Edinburgh under the title Lord Bankton.

The eighteenth century saw the disappearance of the old communal farms. They were replaced by the setup, which in essence survives to the present day - farms with single tenants, or owners, who rotate their crops systematically in enclosed fields often separated by drystane dykes. The growth of industrial towns and cities meant that the market for farm produce widened. Farms supplied more than local needs. Cheese making became a farm staple. Creameries were eventually established in Sandhead and Drummore. On some farms flax for linen-manufacture was grown.

The former tenants of the ferme-touns were rapidly transformed into a new class of farm labourers, with the incidental consequence of much rural deprivation and discontent. The countryside gradually became depopulated as the result of migration to the new industrial towns and cities, or overseas.

The lack of paved roads made land traffic difficult, and with the growth of trade local ports, Drummore in particular, became more important. Traffic was mainly with Ayr, Belfast, Maryport in Cumberland, and Liverpool. Exports included potatoes, cheese, and other farm products. Imports included coal, salt, manure, lime, animal food, and a variety of household goods.

The toll exacted on ships by tides and rocks led to the erection of the Mull of Galloway Lighthouse in 1828. Robert Stevenson, a member of the celebrated family of lighthouse builders, directed the work.

A lifeboat station was opened at Port Logan in 1866, and closed in 1932. The former lifeboat house is now the village hall.

During the nineteenth century some paved roads were constructed, but land traffic was still slow and cumbersome. In 1877 a Galloway MP, M.J. Stewart, proposed the building of a railway from Stranraer southwards to Ardwell, where he lived, with the possibility of a later extension to Port Logan or Drummore. He employed a surveyor to plan the route and estimate the cost. The failure of the City of Glasgow Bank in 1882 put an end to the scheme. Until the early twentieth century stagecoach and carter's wagon remained the only methods of transport by land.