The 1920s was a decade like no other: an era of jazz music, flappers, new-found economic prosperity and emerging technologies, immortalised by author F. Scott Fitzgerald in the pages of the novel The Great Gatsby. Yet outside of popular literature, there were many real-life tycoons who amassed enormous wealth during the so-called Roaring 20s. Using Forbes’ 1918 Rich List, here are the 17 richest men and women of the era – who’d all be billionaires in today’s money.

A prolific railroad tycoon who owned one-seventh of all railroads in the US in his lifetime, Arthur Curtiss James was one of the richest Americans of the 1920s and 30s with a net worth of $60 million in 1918, equivalent to $1 billion (£820m) today. Biographer Roger Vaughan called him the "unsung titan of the Gilded Age", describing him as a man who shied away from attention yet was "a prominent and intrepid yachtsman, generous philanthropist [and] avant garde socialite".

Born in 1867 to copper miner Daniel Willis James and his wife Ellen S. Curtiss, he inherited most of his father’s $26 million fortune after his death in 1907. James built up an extensive rail network after World War I, as well as having holdings in gold, copper and silver mines. Along with his wife Harriet Eddy Parsons, he had an impressive $1 million house (pictured) built on Park Avenue, New York.

Joseph Widener was part of one of America’s richest old money dynasties. He was born in 1871 to real estate magnate Peter Widener and came into a massive $60 million inheritance in 1915 when his father passed away, which equates to $1 billion (£820m) in today's money. Yet, unlike his two brothers, he had little interest in the business world and focused on his passions of art and horse racing instead.

Widener was able to pursue these interests in an ultra-luxurious home. He lived in Lynnewood Hall (pictured), the family’s elaborate, 110-room Georgian-style mansion near Philadelphia, where his extensive personal art collection – including works by Renoir, Manet and Rembrandt – was housed. After his father’s death, he made most of his money from horse breeding and selling, as well as investing in rail, steel and tobacco industries.

Cyrus McCormick Sr. was responsible for one of the most important inventions of the 1800s: the McCormick Reaper (pictured), a piece of farming equipment which allowed grain to be harvested much more quickly and helped the move towards industrial farming. Thanks to this innovation, eldest son Cyrus H. McCormick Jr. inherited a hefty fortune, along with the highly-successful McCormick Harvesting Machine Company when his father died in 1884. His net worth was $60 million in 1918, equivalent to $1 billion (£820m) today.

McCormick Jr. was also member of an elite club called the Jekyll Island Club – known informally as the "millionaires club". This exclusive society was based at a clubhouse in Jekyll Island, Georgia, and included members of some of America’s richest dynasties: the Morgans, the Rockefellers and the Vanderbilts, to name a few. Its regulars entertained themselves through hunting, taxidermy, tennis and golf.

Born into the wealthy Morgan clan, John Pierpont Morgan Jr. took over banking giant JP Morgan & Co in 1913 when his father died. During World War I he served as a munitions purchasing agent for the British government, a controversial role which involved exporting weapons to Britain and France. In 1915, when an assassin named Eric Muenter broke into his Long Island mansion and attempted to kill him, Morgan was shot twice but recovered quickly.

With a net worth of $70 million in 1918, equivalent to $1.19 billion (£980m) today, he may have been one of the wealthiest people in the 1920s, but JP Morgan Jr.’s wealth took a huge hit at the end of the decade as the Great Depression began to take hold. House of Morgan assets fell by 40% during the period and Morgan became a detestable symbol for the untrustworthy world of American banking – immortalised as the 'King of Wall Street' in newspaper cartoons such as the one pictured from circa 1930.

Charles Schwab was responsible for an incredibly important invention you’ve probably never heard of: the H-beam, a steel beam that became essential to the building of skyscrapers. Born in 1862 in Pennsylvania, the steel magnate gained an education from the industry’s most well-known and successful figure, Andrew Carnegie, while working as an engineer at his steelworks.

Yet it wasn’t all rosy for Schwab. Towards the end of the decade, like many of his multimillionaire peers, Schwab began to lose a great deal of money and could no longer fund the lavish lifestyle he lived. Struggling to pay bills, he attempted to sell his house (pictured) but couldn’t find a buyer. Despite being worth $70 million in 1918 – the equivalent of $1.19 billion (£980k) today – when he died in 1939, Schwab was $300,000 in debt.

Daniel Guggenheim’s father, mining mogul Meyer Guggenheim, vowed to make each of his sons a multimillionaire, a feat which he more than accomplished. Daniel Guggenheim, his eldest son, ended up the wealthiest with a net worth of $70 million in 1918, equivalent to $1.19 billion (£980m) today. Described as "short, quick, intense" and "a born general, in whom command was instinctive", Guggenheim took the reins of the family company when his father died.

Yet there was a rift among the Guggenheim brothers. The two youngest, Will and Ben (pictured), were accused by their elder siblings of being lazy and entitled. Meanwhile, they protested they’d been left out of business operations. The feud worsened over the years and, in 1923, left the Guggenheim Brothers company in a rocky state, with several of the brothers having resigned and no clear guidance for the next generation. 

Fortune by (middle) name and by nature, Thomas Fortune Ryan was worth a massive $70 million in 1918, equivalent to $1.19 billion (£980m) today. Ryan grew up in rural Virginia before heading to Baltimore, Maryland in his late teens and setting up a brokerage firm there. He founded the New York Cable Railroad in 1898 and throughout the following decade started making investments in the tobacco industry.

Yet his public image wasn’t great. In 1905, when Ryan bought the Equitable Insurance Industry, it triggered a backlash from the public as he was deemed to be a ruthless, cut-throat businessman due to his dealings in the transport industry. Four years later, he sold his Equitable stock. But his business interests kept growing: he invested in everything from coal mines to typewriters and machine guns, at one point having control of 30 different corporations.

The Astor family earned themselves the nickname of "the landlords of New York" due to the overwhelming amount of real estate they owned in the city. With many buildings and streets still bearing their name today – the Waldorf-Astoria Hotel, Astor Row in Harlem and Astor Avenue in the Bronx, to name a few – it’s clear this family of real estate moguls left a legacy. Vincent Astor, born in 1891, was the eldest child of John Jacob Astor IV.

When his father died in 1912 on the Titanic’s maiden voyage, 20-year-old Astor was left with a huge inheritance which included Ferncliff, the family’s 2,800-acre estate near New York (pictured). Yet he was keen to shake up the family’s image of being miserly landlords and set out on more socially beneficial projects, developing housing in poor neighbourhoods such as the Bronx and Harlem. In 1918, his net worth was estimated at $75 million, equal to $1.27 billion (£1.03bn) today.

The wife of railroad executive EH Harriman, Mary Williamson Averell inherited her husband's business empire, valued at between $70 and $100 million, when he died in 1909. She became dedicated to philanthropy, fulfilling his vision by creating a State Park in New York, donating 10,000 acres of their Arden Estate towards the project.

The generous widow also donated to a variety of causes, including The Boys’ Club of New York, the American Red Cross, Yosemite Valley and Yale University. In 1918, her net worth was estimated to be $80 million, which works out as $1.36 million (£1.1m) in today’s money.

Edward H. R. Green was the son of Hetty Green, a notorious penny-pincher who earned the nickname of 'The Witch of Wall Street' for her stinginess. He received an introduction to her harsh ways early on in life when he’d injured his leg and his mother tried to take him to a charity hospital for the poor, refusing to pay for his treatment when they turned him away. As a result, his leg had to be amputated.

His mother (pictured) passed away in 1916, leaving Green with half of her fortune and his sister Sylvia with the other half. Green looked after the family businesses in real estate and transportation, as well as pursuing his own interests as an avid collector. Yet when it came to money, he couldn’t have been more different from his infamous mother, spending on a lavish social life, parties and women. In 1918, his net worth was estimated to be $100 million, which equates to $1.7 billion (£1.4bn) today.

He may have died in 1920 but there’s no doubt that William Kissam Vanderbilt, along with the rest of his family, left a lasting impact on the decade. Born in 1849, the grandson of Commodore Cornelius Vanderbilt, who is frequently listed as one of the richest Americans of all time, William grew up in a world of immense wealth, inheriting $55 million from his father when he died in 1885. This contributed significantly to his net worth of $100 million in 1918, which would be $1.7 billion (£1.4bn) today.

Vanderbilt took an interest in thoroughbred horse racing, becoming a key shareholder in prominent horse racing clubs and building the American Horse Exchange in New York in 1896. Like other family members, he built many lavish homes, including a mansion on Fifth Avenue and an elaborate Château in Carrières-sous-Poissy, France (pictured).

The automobile titan who is famous for inventing the assembly line (pictured), Henry Ford made a huge mark on the industry – and racked up a fortune along the way. Born in 1863, Ford showed an aptitude for mechanics from early in life, when at age 13 he was given a watch by his father and managed to take it apart and repair it by himself. He went to work as an apprentice at a machinery firm at the age of 16.

After gaining further experience from an engineering role at the Detroit Edison Company, in 1896 Ford constructed his first model car, the Ford Quadricycle. The Ford Motor Company was established in 1903 and one of the company’s first cars, the Model T, made owning an automobile more accessible to a large slice of the American population. With a net worth of $100 million in 1918, which is equivalent to $1.7 billion (£1.4bn) today, Henry Ford was one of the wealthiest Americans of the decade.

An American entrepreneur who made his fortune through the meatpacking industry, J Ogden Armour was the son of Philip Danforth Armour Sr., who was partner in the meatpacking firm Plakington & Armour (later renamed Armour & Co). In 1901, shortly after his father’s passing, Armour took on the role of president of the company. He was worth $125 million in 1918, equivalent to $2.12 billion (£1.75bn) today.

Under his guidance, sales skyrocketed from $200 million to $1 billion – but it wasn’t all rosy. In 1904 there was a strike across the meatpacking industry, which Ogden got around by hiring strikebreakers, in violation of the terms of the union. The federal government tried to sue him, but the case was let go. Then between 1919 and 1921 the company got into big financial trouble, losing $125 million due to a post-war sales slump.

The sixth richest person on Forbes’ 1918 Rich List, Edward S. Harkness was worth $125 million, which would be $2.12 billion (£1.75bn) today. His wealth was largely thanks to an inheritance from his father Stephen V. Harkness, a key shareholder in Standard Oil, and his older brother Charles W. Harkness. 

Although less well-known than the biggest charitable donors of his era – John D. Rockefeller who gave away more than $500 million throughout his lifetime, and Andrew Carnegie who donated $325 million – Harkness was a major philanthropist, donating in excess of $100 million throughout his life. He was a major benefactor of the New York Public Library and the Metropolitan Museum of Art and made generous gifts to universities including Columbia, Harvard and Yale. He set up the Commonwealth Fund with his mother, which is housed at Harkness House in New York (pictured).

William A. Rockefeller Jr. was the son of a notorious con artist William Avery Rockefeller Sr., and co-founded Standard Oil along with his older brother John D. Rockefeller – who’d go on to be the richest person in modern history. With an enormous net wealth of $150 million in 1918, equivalent to $2.54 billion (£2.09bn) today, William Rockefeller was the third richest person in America at the time.

Born in 1841 in New York, Rockefeller started an oil refinery in Ohio in 1865, which went on to become Standard Oil in 1870 following a merger with his brother’s firm. He branched out into the copper mining, railroad and banking industries, though it was oil he was most famous for. In a German cartoon created in 1903, he was depicted as one of the three kings of American industry, along with 'trust king' JP Morgan and 'steel king' Andrew Carnegie.

Less well-known than JP Morgan yet ultimately wealthier, George F. Baker was a leading financier of the decade, earning him the nickname the "Dean of American Banking". But he didn’t have a traditional route to success. The son of a shoe store owner, he did not attend university and worked as a clerk at the New York State Banking Department from the age of 16, before enlisting in the volunteer army during the Civil War.

Yet he put his banking knowledge to good use. In 1863, Baker cofounded the First National Bank of New York City, along with a man named Jon Thompson and Thompson’s two sons. He was also a major shareholder in steel and railroads and lived the high life, being a member of the legendary Jekyll Island Club and owning three luxurious properties – one of which was an estate in Tuxedo Park, New York (pictured). In 1918 Baker was worth $150 million, equal to $2.54 billion (£2.09bn) today.

John D. Rockefeller set a new benchmark for wealth in 1916, when he became the first ever billionaire. With a net worth of $1.2 billion in 1918, equivalent to $20.36 billion (£16.78bn) today, the oil tycoon is often considered the wealthiest person of all time, given that his net worth was 2% of the national economy at the time. 

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Along with his brother, Rockefeller set up Standard Oil in 1870, which went on to have a near-monopoly of the industry by 1882. His overarching influence over the oil business was a cause for concern, with many journalists and political figures protesting the company’s controversial practices such as underselling competitors and using differential pricing. Rockefeller was also an influential philanthropist, donating an astonishing $530 million throughout his life to various causes.

Find out where Rockefeller ranks among the 20 richest people of all time