The original expropriation of oil built as many as half of the greatest fortunes of the twentieth century.

The claim is hedged ('as many as half'), so it is an upper-bound estimate. It also assumes that oil was originally 'expropriated', meaning taken from producing countries or their peoples on unfair terms, and that this built great fortunes. True: credible lists or historical studies of the greatest 20th-century fortunes (for example inflation-adjusted rankings of the richest people of the century) show that oil-derived fortunes made up close to half of the top group (roughly 40% or more of a reasonable top list such as the top 10 or top 20), and that these fortunes depended on cheap access to oil in places such as the Middle East, Latin America or other producing regions. Mostly true: oil fortunes are a large share (about 30–40%), or the share is near half but only some of those fortunes rest on foreign or expropriated oil. Mixed: oil fortunes are a clear but modest share (about 15–30%), or the share is large but the 'expropriation' framing fits only a minority of them. Mostly false: oil accounts for only a small share (under about 15%) of the greatest fortunes, or the major oil fortunes came mainly from domestic production unrelated to any expropriation, so the claim overstates a real but limited link. False: the evidence shows oil fortunes were a negligible part of the century's greatest fortunes.

Set before the research began.

1. E1 The richest Americans every decade over the past 100 years | lovemoney.com loveMONEY.com · 22 June 2026

   “Around one-fifth of the fortunes listed came from the oil industry, while just 3% were via the burgeoning technology sector.”

2. E2 The richest Americans in history History News Network (republishing CNN's Steve Hargreaves) · 1 June 2014

   “By 1880, Standard controlled 90% of the oil produced in the United States.”

3. E3 The richest Americans every decade over the past 100 years | lovemoney.com loveMONEY.com · 22 June 2026

   “A ruthless businessman, Hunt primarily made his fortune through his vast portfolio of oil holdings.”

4. E4 List of richest Americans in history Wikipedia · 5 November 2009 Own record

   “For this reason, there is not one decisive ranking of the richest Americans in history.”

E1 reports that about one-fifth of the fortunes in a decade-by-decade list of the richest Americans came from the oil industry. That share is a clear but modest one, inside the criteria's 15–30% 'mixed' band and well below the 'as many as half' in the claim. E2 says that by 1880 Standard controlled 90% of the oil produced in the United States, which concerns domestic production and does not fit the 'expropriation' framing. E3 confirms Hunt's fortune came mainly from oil but does not say where the oil came from. E4 notes there is no single authoritative ranking, and the evidence covers only Americans, so the overall share cannot be pinned down more precisely.