An active Whig from 1796 until 1826, William Alexander Madocks was also involved in developing Portmadoc (Porthmadog) and the Ffestiniog Railway in the 1820s.
William Madocks was born in London on 17 June 1773 to middle-aged parents. At the age of eleven, he went to Charterhouse boarding school, and spent five and a half years there, but left in December 1789, when it appears that the Founder's Day celebrations got out of hand, and William refused to submit to a flogging of the whole class. His father backed his stance, and he worked briefly in a country solicitor's office before going to university at Oxford. His father hoped that he might also pursue a career in the legal service.
In 1796 Madocks purchased the Dolmelynllyn estate, using inheritance from the death of his father. He was attracted to the location due to its proximity to the waterfalls of Rhaeadr Ddu, Pistyll Cain and Rhaeadr Mawddach.
In 1798, he bought the Tan-yr-Allt estate, on the western bank of Traeth Mawr, a large expanse of sand and tidal marsh which formed the estuary of the Afon Glaslyn. He set about extending his property by reclaiming Penmorfa Marsh from the estuary, and growing wheat and rape on the reclaimed land, and planted barley and grass.
In 1800, the British government and the Irish government both passed Acts of Parliament which created the United Kingdom of Great Britain and Ireland. The Union with Ireland meant that there was a need for improved communication between the two countries, and Madocks was in favour of a route which crossed his estate, to reach Porthdinllaen, on the northern coast of the Llŷn Peninsula, which would provide the terminus for a ferry to Dublin. However, this route involved a crossing of the dangerous Traeth Mawr sands, near the mouth of the Afon Glaslyn, or a lengthy detour to the north to cross the river at the Aberglaslyn bridge. The alternative ferry route from Anglesey involved crossings of the River Conwy and the Menai Strait, bridges over both of which had not yet been built. Madocks therefore, emboldened by the success of his first embankment, revived a plan first proposed in 1625 by Sir Hugh Myddleton, and reconsidered in 1718 and 1770, for a more substantial stone-filled embankment across the mouth of the river Glaslyn. This would enclose some further 6,000 acres (24 km2) whilst providing safe passage across the estuary.
The Porthdinllaen Turnpike Trust Act was obtained in 1803, and in 1807 Madocks succeeded in steering the Porthdinllaen Harbour Bill through parliament. He also promoted the building of turnpike roads, as part of his plan to open up the area and increase its prosperity. Construction of Tremadog continued. In 1805, work began on a water-powered woollen mill, which was overseen by the engineer Fanshaw. It was one of the first such installations in North Wales, but Madocks was not impressed by Fanshaw, who was dismissed in 1806.
Madocks asked Creassy to design the planned embankment and dam across Traeth Mawr, and in early 1806, attempted to obtain an Act of Parliament to authorise it. Madocks hoped the work would be finished by May 1809, but the work proved to be more difficult than expected.
Disaster struck in February 1812, when a storm and high tides breached the embankment. The cost of the project had been about £60,000, much more than Madocks' first estimate, and he was in no position to finance further work. Samual Girdlestone, to whom Madocks owed £30,000, obtained a warrant on 24 March, but by the time he arrived at the estate, the land had been transferred and only Madocks personal property remained. To prevent other creditors making the estate worthless, Girdlestone bought it at its valuation cost, and became the tenant of Tan-yr-Allt. Madocks was effectively bankrupt, but was never declared to be so, and his Parliamentary immunity again saved him from prison. Finally, in 1814, the breach in the embankment was repaired, and it was open for traffic again.
In 1814, he had a severe attack of gout and rheumatism, but sold some property in Denbighshire and recovered enough to visit France. He returned, enthusiastic to complete a bridge over Traeth Bach, the estuary of the Afon Dwyryd, which would create a route from his embankment to Harlech and Trawsfynydd. In Parliament, he was vigorously opposing the property tax, which had been introduced to fund the war against Napoleon, and opposing the repeal of the habeas corpus Act, to prevent imprisonment without trial.
Madocks was again elected to Parliament by the people of Boston in 1818, but it was the last time he represented them, as later that year he married Eliza at Talgarth, and spent much more time at Tregunter. Still suffering from illness, the journey to Boston from Tregunter was difficult, and from the election of 1820 he represented Chippenham in Wiltshire.
Madocks had always had a regional plan in his mind, which involved improving communications and creating industry. At Blaenau Ffestiniog the quarrying and mining of slates was hampered by the difficulties of getting them to market. A harbour was authorised, and could be used by vessels up to 60 tons by late 1824. Williams was by this time the Director of Works for the newly named Port Madoc Harbour, and took on responsibility for the railway plans, as Madocks was suffering from jaundice. A rival scheme, backed by the banker Meyer Rothschild, was proposed to run down the Croesor Valley on the other side of the Moelwyn mountains, but included inclines over the hills to reach Blaenau Ffestiniog. The line proposed by Provis was rejected in Parliament, in favour of Rothschild's route, but then local landowners became suspicious of the rival scheme, and it too was defeated.
Meanwhile, Madocks became a father when his daughter Eliza Anne Ermine was born. With Madocks' health deteriorating, his wife decided he needed a long holiday. Having crossed Italy and Switzerland, the party stayed in Paris, where Madocks died on 15 September 1828. He was buried on 17 September atPère Lachaise Cemetery, while a brass plaque was put up to his memory at St Mary's Church in Tremadog.