However, the area's fortunes changed when the Milbankes sold their estates to the third Marquess of Londonderry, who built a harbour in 1828 to facilitate transport of goods from the industries they encouraged on their land. However, this harbour later proved inadequate to deal with the millions of tonnes of coal being mined from their nearby mines, and the sixth Marquess commissioned engineers Patrick Meik and Charles Meik to reclaim land and extend and deepen the dock. This was officially opened in 1905.
Today, the town has a population of around 22,000.