By the early part of the twentieth century, the traditional line fishing had given way to more modern methods and the scene of women baiting the lines with mussels at the harbour had disappeared. Although the squared out holes in the rocks beyond the paddling pond in the East Bay, known as the 'drippin' pans', continued to be used for gathering salt and holding lobsters. The town was now supplied by water from the Thorter and Dunolly reservoirs situated above Garvald in the Lammermuirs with storage since 1881 of 179,298 gals at the Heugh Farm. There were a number of societies active in the town including the Freemason's, Foresters', Oddfellows and Good Templars'. The old tenement known as the 'Gunboat' was demolished to make way for the Ben Sayers golf club factory, on the site now occupied by the building at 15-21 Forth Street. During the factory excavations a 14th century kiln, 25 feet high was unearthed. In earlier times this had been used to dry barley when the Dirleton Granary occupied this site.

In 1902 work began on a new cemetery in Dunbar Road. The town hearse was independently financed by the Hearse Society and in 1904 it was used 34 times compared with 66 times the previous year, reflecting the health of the community. The gas company introduced a new street lighting system in 1905. The apparatus consisted of a little tank and bell which were actuated by extra pressure from the gasworks, forcing the bell to raise, opening the valve and allowing gas to press to the burner. The result being that lamps which extended over a wide area could be lighted within a few seconds of the increased pressure. By reducing the pressure at the works the valve was closed and the light extinguished. The gas company presented the Town Council with two decorative street lamps each with the Burgh coat of arms engraved on the glass. One lamp was erected at the foot of the stairs leading to the Council Chambers and the other outside the residence of the current Provost, which for over 70 years was traditionally moved each time a new provost was elected.

During this period North Berwick experienced an amazing boom in property building - Marmion Road (1885), St. Margaret's Road (1899), Dirleton Avenue (1901), York Road (1902) and St. Baldred's Road (1907). Clifford Road was named after Alice Clifford, wife of the 8th Baronet, Sir Walter Hamilton-Dalrymple. This tradition of naming roads after the Baronet's wife continues to this day. Some of the finest buildings were designed by Robert Lorimer from 1893 - 1909, The Grange, Bunker Hill, Carlekemp, Teviotdale formerly Greyholme, Westerdunes and Hyndford, using Rattlebags stone quarried at East Fenton and the finest craftsmen. St Anns in York Road, owned by the Dowager Countess of Camperdown was a typical residency built for the nobility. By the 1870s, St Anns was occupied by Lady Elizabeth Duncan, daughter of the first Earl of Camperdown, and grand-daughter of the celebrated Admiral Duncan, who in 1797 defeated the Dutch, under Admiral de Winter in the great naval battle of Camperdown in Holland and was on that account created Lord Duncan. In 1811, the Right Honourable Lord Viscount Duncan was the last to be admitted an ordinary burgess of North Berwick in right of his spouse Janet Dalrymple.

The advent of rail transport resulted in the rapid expansion of agriculture in the area, despite a set-back in 1879 when shiploads of cheap American grain started to arrive in Britain. Also around this period a number of important innovations were taking place, including the invention of the threshing drum by Meikle at Preston Mill which is used to this day in the latest combine harvesters, and the steam-plough introduced to the Lothians on Ferrygate farm. Agriculture was still dominated by the horse, and during the Spring it was not uncommon for the farm worker to walk for eleven straight weeks behind a pair of horses, pulling various implements. The ploughman's cottage with one outdoor pump to supply water for 6 or 8 families with no indoor or in some cases outdoor conveniences would not be modernised until the 1950s with electric light and a bathroom.

In June 1905, the North British Railway Company introduced a motor vehicle service from North Berwick to Aberlady, offering better access to the coastal villages. Two vehicles were built by the Mo-Car Syndicate in Paisley to operate the hourly service from the railway station at North Berwick. The vehicles were fitted with a three-cylinder Arrol-Johnston engine, the gear-box was by Renold with a silent side chain to the rear axle, giving four speeds forward and one reverse. The solid tyres were to prevent punctures, and the body work was in varnished walnut. The motor was of the charabanc type carrying 23 passengers, with accommodation for luggage and parcels under the seating compartment. On Saturday 10th June 1905, a trail run was made from Edinburgh to North Berwick, when the journey was completed in 1 hour 30 minutes. The service to Aberlady started the following Monday, with the fare from North Berwick to the three villages being fourpence each stage, the full journey to Aberlady costing one shilling.

From 1790-1870 the industries in which Scotland excelled - textiles, iron and coal required a cheap and abundant labour force with little or no skill. The development of Neilson's Hot Blast in 1828 using hot air in the smelting of iron, permitted the exploitation of Scotland's vast reserves of coal and blackhand ironstone (a native iron-ore).

From 1870 onwards the direction of Scottish economic development began to shift towards a greater degree of specialisation. As other modern industrial nations moved towards mass production, Scotland retained craftsmanship in design and production. Nowhere in the world, it was argued could you find better companies and engineers to design and build high quality ships, engines, locomotives and heavy machinery to such exact standards and specifications. This was a golden era for North Berwick with many wealthy industrialists building property in the town as their summer residence and the local economy flourished.

On the eve of the First World War, the Clyde produced 18% of all the ships launched in the world that year and the Scottish shipbuilding industry was bigger than that of Germany or the United States. Glasgow was the largest locomotive production centre in the world and Scotland produced about 20% of the steel made in Britain. With only 10% of the population, Scotland accounted for 17.5% of all manufactured goods in the UK.

The 1914-18 war brought uncertainty and hardship with 152 of the towns men folk loosing their lives in active service. The recruitment policy during the Great War was to keep men from the same area together, this meant that casualties were usually specific to local recruiting areas. As 'Pals' fought together, more often then not they died together. This meant that local communities experienced collective mass grief rather than individual loss. An unlucky shell could wipe out a third of the adult male population of a small town. The War Memorials in every town and village are testament to the sacrifice made by rural society.

One of the most famous 'Pals' regiments was 'C' company of the 16th Royal Scots, known as 'McCrae's Battalion'. Raised by Colonel Sir George McCrae in November 1914 and among those who enlisted was the entire Heart of Midlothian football team. McCrae's Battalion was blooded in the Battle of the Somme in 1916, losing three-quarters of their strength on the first day alone when seven Hearts players lost their lives and eleven others wounded or gassed. McCrea commanding the regiment was himself invalided home. In time, the battalion recovered. It came of age at Arras, endured the muddy horror of Passchendaele, and held the line unbroken in the face of furious German attacks on the Lys in 1918.

Sir George McCrae who came from a poor background, clawed is way to become a pillar of the Edinburgh establishment and was elected Member of Parliament for East Edinburgh in 1899. He died in 1928 at his home at 9, Tantallon Terrace, North Berwick, aged 68 years. His funeral was the largest ever witnessed in Scotland. Businesses closed, traffic suspended and the southside of Edinburgh came to a standstill with thousands of mourners lining the streets to the Grange Cemetery. The clock tower that stands at Haymarket in Edinburgh, (unveiled in 1920 to a crowd of 40,000) is dedicated to the players and supporters of Heart Of Midlothian FC who died serving in 'McCrae's Battalion'.

The first ship sunk in WW1 was HMS Pathfinder when it was torpedoed in the Forth Estuary on 5th September 1914. This action was later credited to a German agent Carl Lody who was spying on the British fleet in the Firth of Forth. Lody sent a telegram to his contact in Stockholm with the coded message that several large warships were leaving Rosyth. The light cruiser was intercepted by a German U- boat and 256 of her crew were killed. Lody using a false American passport and calling himself Charles Inglis was arrested by Scotland Yard on 2nd October 1914. He denied spying, but his overcoat carried the mark of a Berlin tailor and the name C. H. Lody was sewn inside. Carl Hans Lody was found guilty of treason and executed by firing squad on 6th November 1914 in the Tower of London.

Following this breach of security, the Royal Navy top secret base in the outbuildings of Seacliff House was the landfall site of the easternmost line of detector loops that ran across the entrance to the Firth of Forth. The other line ran to the east of the May island and made landfall at Crail (RNAS Jackdaw). These 'detectors' were huge lines of hydrophones laid in a series across the seabed to detect U-Boots entering the Firth. It must have been a skilled and intensive task, listening to underwater noise, as apparently the operatives only did two hours 'on watch' before being relieved.

East Fortune was established in 1915 as a Royal Naval Air Station to combat the anticipated threat from Zeppelins. During WW1 airships flew from East Fortune to carry out fleet spotting and submarine hunting duties. From 1918 aircrews were trained on the beach at Belhaven Sands in torpedo dropping techniques. This was pioneering work as the world's first torpedo dropping aeroplane that could operate from aircraft carriers (Sopwith T.I Cuckoo) was stationed at East Fortune.

The government rented houses for the duration of the conflict to accommodate the servicemen and one such was Carlekemp in Abbotsford Road which was used as an officers convalescent home. The name Carlekemp means - 'camp of the young men' and one officer recalls seeing the long procession of the surrendering German Fleet, 70 warships steaming up the Forth, while in the foreground a leather booted horse was drawing a mower over the fairways.

The airship R.34 lifted off from East Fortune to cross the Atlantic on 2nd July 1919 with a crew of 30, crossing the Nova Scotia coast in 59 hours. Then on to New York before the return journey taking 75 hours to become the first airship in history to complete the double crossing of the Atlantic. The R.34 was constructed in William Beardmore's gigantic airship works at Inchinnan outside Glasgow, and transported to East Fortune. The wire used on the airship was supplied by Brunton Wire Works at Inveresk. The company established in 1902, originally produced piano wire and were pioneers in the development of wire used in the early biplanes.

Following the Great War the higher cost of living, increased Income Tax and Death Duties meant that the numbers of staff employed in the larger summer houses had to be scaled down and in some cases the mansions were sold.