The War of the Pacific (1879–1883) provided North with an opportunity to purchase large numbers of bonds in the Peruvian nitrate industry.

When Chile annexed Iquique and the surrounding province of Tarapacá the Chilean government transferred ownership of the nitrate fields to the bondholders.

North built upon his nitrates business by expanding into further monopolies in waterworks and freight railways, but also owned several iron and coal fields.

[3] During the war, North was assisted by two British men: Robert Harvey, who had worked for the Peruvian government in the nitrates (saltpetre) industry, and John Dawson, a banker.

[4] After the war, the Chilean government annexed Tarapacá and allowed the bond holders to take possession of the title deeds to the nitrate fields, perhaps influenced by appeals from North's friends.

[3] North thus managed to secure a large share of the Chilean nitrate industry for a very small initial investment in almost worthless bonds.

By allowing the speculators to start mining the Chilean government could take a share of profits via export duties without having to provide the initial capital costs to begin production of nitrates.

[6] North left Chile and returned to the United Kingdom in order to raise credit to provide for machinery, transport and employment costs.

[2] He was the owner of a 600-acre (2.4 km2) estate with extensive stables and a mansion, Avery Hill, near to Eltham in Kent, which was subsequently acquired by the LCC and opened as a ladies teacher-training college in 1906.

[1] North visited the United States in July 1889 where he was described as a member of the nouveau riche and a "Chilean Monte Cristo" because of his recent rise to fame and fortune.

[1] North was approached by King Leopold II of Belgium at a horse racing event to provide funds to establish a concession company to extract rubber from the Congo Free State.

[11] North agreed and provided GBP£40,000 of the BEF250,000 initial investment to set up the Anglo-Belgian India Rubber Company (ABIR) at Antwerp on 6 August 1892.

[12][13] ABIR had exclusive rights to all forest products from the Maringa-Lopori basin for 30 years and had police powers within the limits of the concession to enforce the collection of rubber as a tax.

[15] Despite his varied investments across the world North's finances eventually dwindled, his decline was accelerated by the Chilean Civil War.