By one estimate, [[J. P. Morgan]] (1837–1913) is believed to have been the 24th richest American in history,<ref>{{cite web|title=The Wealthiest Americans Ever|url=https://www.nytimes.com/ref/business/20070715_GILDED_GRAPHIC.html|website=The New York Times: Business|access-date=7 October 2014}}</ref> inflation-adjusted. His fortune is believed to have grown to about $57 billion (2024 USD).
According to historians Michael M. Klepper and Robert E. Gunther, Morgan had one of the highest wealth:GNP ratios in American history. In their book, ''The Wealthy 100: From Benjamin Franklin to Bill Gates'',<ref>{{Cite book|title=The Wealthy 100: From Benjamin Franklin to Bill Gates|isbn=0-8065-1800-6|url=https://archive.org/details/wealthy100frombe00klep|last1=Klepper|first1=Michael M.|last2=Gunther|first2=Robert E.|year=1996|publisher=Carol Publishing }}</ref> Morgan's wealth:GNP ratio was 328.<ref>{{cite web|last1=Roth|first1=J. D.|title=The Wealthy 100: A Ranking of the Richest Americans, Past and Present|date=14 October 2008 |url=http://www.getrichslowly.org/blog/2006/07/29/the-wealthy-100-a-ranking-of-the-richest-americans-past-and-present/|publisher=Get Rich Slowly|access-date=7 October 2014|archive-url=https://web.archive.org/web/20141011013125/http://www.getrichslowly.org/blog/2006/07/29/the-wealthy-100-a-ranking-of-the-richest-americans-past-and-present/|archive-date=11 October 2014}}</ref> At the time, his fortune equaled around $119 billion.