McKinsey Turns 100: The Untold Story of the World's Most Powerful Consulting Firm
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In 1926, a University of Chicago accounting professor named James McKinsey decided to help companies make better decisions. One hundred years later, the firm he founded advises 80 of the 100 largest companies in the world, operates in over 65 countries, employs roughly 45,000 people, and has been at the center of some of the most consequential business decisions — and scandals — in modern history.
We spent 6+ years each at McKinsey. It's our former employer. And as the firm turns 100 in 2026, we thought it was worth looking back at the full story — the brilliant innovations, the spectacular failures, and everything in between.
This is going to be a long one. We'll cover four chapters: how the firm was born, how it shaped modern business, the controversies that nearly brought it down, and what the firm looks like at 100. Let's start at the beginning.
Chapter 1: A Firm Is Born
Chicago, 1926. Jazz is everywhere, Prohibition is failing spectacularly, and James Oscar McKinsey — "Mac" to his friends — has a big idea.
Mac wasn't your typical businessman. He was an accounting professor who had written books on budgeting and financial management before most companies even had a real finance function. His radical idea? That management itself could be a profession. That someone from the outside — an expert — could walk into a company, analyze it objectively, and tell leadership exactly what to do.
This sounds obvious now. In 1926, it was genuinely revolutionary. He didn't even call his people "consultants." They were "management engineers."
McKinsey believed that if you applied the same rigor to running a business as an engineer applies to building a bridge, you'd get better results. He developed a famous 30-page checklist — the General Survey Outline — to systematically evaluate any company's finances, organization, and competitive position. Thirty pages. For a checklist. In 1931.
The Tragic End and the Second Founder
Mac McKinsey's story has a sad ending. In 1935, he temporarily left his own firm to turn around one of America's most iconic retailers — Marshall Field's in Chicago. The turnaround worked. But the stress apparently did not agree with him: James McKinsey died in 1937, at just 48 years old.
His death nearly tore the firm apart. Partners squabbled, offices split off. It looked like the McKinsey experiment might be over before it really began.
Enter Marvin Bower.
Bower had joined in 1933 to run the New York office. After McKinsey's death, he essentially took over and became what historians now call the firm's second founder — and arguably the one who really built what we know today.
Bower was obsessed with making management consulting a true profession, like law or medicine. He created the "up or out" culture, the insistence on hiring only the best, and the fiercely competitive recruitment process that McKinsey is still known for. He introduced the principle that consultants should always put client interests first.
And consultants today still know his name. The shortcuts and tools available to McKinsey consultants are in what the firm calls "Marvin's Toolbox."
Under Bower, McKinsey's billings went from $2 million in 1950 to over $200 million by the time he stepped down in 1967. That's 100x growth in 17 years, from one man's obsession with professionalism.
Chapter 2: How McKinsey Shaped Modern Business
McKinsey got big. But what did they actually do that mattered? Because a company can be big and powerful and still just be noise.
McKinsey wasn't noise. Love them or hate them, they genuinely introduced ideas and frameworks that changed how business is done globally. Here are the greatest hits.
The White House and NASA
Let's start with the hits that most people have no idea McKinsey was behind.
In 1952, McKinsey advised the incoming Eisenhower administration and recommended the creation of a new role in the White House — the Chief of Staff. That role still exists today. McKinsey basically designed the organizational structure of the executive branch of the United States government.
In 1958, McKinsey helped design the original organizational structure of NASA — right before it launched the space program. The agency that put humans on the moon was structurally blueprinted by a consulting firm from Chicago.
The Barcode
Here's one that will genuinely surprise you. The barcode — those black and white lines on literally every product you have ever bought — McKinsey was central to making it happen.
In 1970, McKinsey organized the "Ad Hoc Committee of the Grocery Industry," bringing together senior executives from across the sector. Their mission: create a universal, standardized product code. Working with the committee, McKinsey helped develop a standardized 11-digit code for identifying products, then sent out a contract tender to companies like IBM, RCA, and NCR to build the system.
IBM won that tender. The result was the Universal Product Code — the UPC. On June 26, 1974, a 10-pack of Wrigley's Juicy Fruit gum was scanned at a Marsh Supermarket in Troy, Ohio — the first commercial use of the barcode. That pack of gum is now in the Smithsonian.
Today, barcodes and their derivative QR codes are scanned billions of times a day worldwide. The entire modern supply chain runs on this standard. And it exists because a consulting firm got a roomful of grocery executives to agree on eleven digits.
The 7S Framework and "In Search of Excellence"
McKinsey shaped how we think about business theoretically, not just practically. Their 7S Framework argued that seven elements of an organization — Strategy, Structure, Systems, Staff, Skills, Style, and Shared Values — all have to be aligned for a company to work. Change one, and all the others shift. What was novel was the strong focus on soft factors, describing business as a holistic, interdependent system rather than a purely top-down structure. The framework is still taught at business schools decades later.
From that same research came something even bigger. In 1982, McKinsey consultants Tom Peters and Robert Waterman published "In Search of Excellence" — a study of 43 top American companies. It became one of the best-selling business books of all time, moving over three million copies in its first four years. A 2002 panel convened by Forbes rated it the most influential business book of the 1980–2000 era. "In Search of Excellence" basically launched the entire popular business book genre. Every airport bookstore bestseller since traces a direct line back to that book.
The Thought Leadership Machine
McKinsey has published the McKinsey Quarterly since 1964 — one of the most influential business publications in the world. The model — publish ideas, build credibility, convert readers into clients — is now copied by every major consulting firm, law firm, and bank. McKinsey essentially invented modern B2B content marketing. In 1964.
The Alumni Network
Perhaps McKinsey's most underrated legacy: its alumni network. The "up or out" model means most people who join eventually leave. And those people go on to run the world at a staggering rate. Former McKinseyites have led Google, IBM, American Express, and dozens of other major corporations. McKinsey alumni have run governments and central banks. The firm has produced 70 Fortune 500 CEOs — earning it the title of the world's CEO factory.
When McKinsey advises a company run by a McKinsey alum, using a framework from a McKinsey-published book, while billing fees tracked in a McKinsey-designed system — that's what 100 years of institutional influence looks like.
Chapter 3: Controversies and Criticism
We've celebrated the wins. Now let's talk about the other stuff. Because for all its brilliance, McKinsey has been involved in some of the most spectacular business failures and genuine ethical scandals of the last 50 years.
Enron: "We Loved Their Business Model"
Remember Enron? The energy company that collapsed in 2001 in one of the biggest accounting frauds in American history? McKinsey was Enron's longtime consultant. And McKinsey didn't just advise Enron — they celebrated Enron's business model publicly. The McKinsey Quarterly published articles praising Enron's off-balance-sheet structures and encouraging other companies to adopt them.
The CEO of Enron who went to prison — Jeff Skilling? Former McKinsey consultant. Many of the ideas that drove Enron off a cliff were hallmarks of McKinsey thinking at the time.
The Opioid Crisis: The Billion-Dollar Lesson
This is the one that shook the firm to its core. McKinsey was hired by Purdue Pharma when OxyContin sales were declining. McKinsey's job? Figure out how to sell more of it. And they did — developing strategies to "turbocharge" sales, including targeting doctors more likely to prescribe heavily. McKinsey earned approximately $86 million for this work.
When the full scope of involvement became public, the backlash was enormous. The firm eventually agreed to pay approximately $1 billion in total settlements. In late 2024, McKinsey agreed to a $650 million settlement with the U.S. Department of Justice — one of the largest penalties ever paid by a consulting firm.
South Africa and State Capture
McKinsey's local operations became entangled in South Africa's "state capture" scandal — a systematic corruption network surrounding then-President Zuma and the Gupta family. McKinsey partnered with a Gupta-linked subcontractor to win contracts with Eskom, South Africa's state power company, potentially worth $700 million — what would have been the firm's largest single fee ever in Africa.
Insider Trading at the Top
Rajat Gupta — McKinsey's Global Managing Director for nine years — was convicted in 2012 of insider trading, tipping off a hedge fund about confidential information from his Goldman Sachs board seat. A senior partner, Anil Kumar, also pleaded guilty to selling confidential client information.
Advising Authoritarian Governments
McKinsey has faced sustained criticism for advising governments with poor human rights records. In 2018, it emerged that a McKinsey project in Saudi Arabia had identified Twitter accounts critical of the government — information allegedly later used to target those individuals. More recently, McKinsey's work with Chinese state-linked entities drew U.S. political scrutiny, leading to significant restructuring of its China operations.
Chapter 4: McKinsey Today and Its Future
McKinsey turns 100 at a genuinely uncertain moment. The consulting industry is being disrupted. AI is automating things consultants used to get paid handsomely to do. And McKinsey — the firm that built its brand on always having the answer — is doing some genuine soul-searching.
The Rough Patch
After the opioid settlements and significant drops in client demand, McKinsey made a series of painful cuts. In 2023, "Project Magnolia" eliminated 2,000 jobs. In 2024, another round targeted design, data, and software specialists. And in 2025, the firm announced cuts of approximately 5,000 more jobs — about 10% of the global workforce.
Meanwhile, competitor BCG reported 10% revenue growth in 2024. That stung.
McKinsey and AI: Meet "Lilli"
In 2023, McKinsey launched an internal AI tool called Lilli — a proprietary generative AI system that lets consultants search decades of the firm's knowledge base, generate presentations, draft reports, and synthesize research. By late 2025, roughly 72% of McKinsey's workforce was actively using it, with the firm claiming it saves consultants 30% of their research time.
The irony is profound. McKinsey spent decades charging companies enormous fees for human analysis and insight. Now McKinsey itself is deploying AI that automates a meaningful chunk of that work. If AI can do the research, the synthesis, the framework application — what exactly is McKinsey selling? The answer, presumably, is judgment, relationships, and execution. But that's a much harder thing to price at $500,000 a week.
Four Things to Watch
As McKinsey enters its second century, here are the four questions that will define its next chapter:
Can it rebuild trust? The opioid crisis and South Africa scandals did real reputational damage. Reputation repair takes longer than settlement payments.
How does it price in an AI world? The shift from billing for hours to billing for outcomes is slow and hard. McKinsey will have to get there eventually.
What happens to the talent model? If Lilli replaces junior analyst work, you need fewer junior analysts. The famous "up or out" pyramid may need to be redesigned from the bottom up.
Will the alumni network hold? McKinsey's ultimate moat has always been its people. As long as McKinsey alumni run the world, the firm has a structural advantage. The question is whether that network continues to self-reinforce in an era of more distributed information and talent.
The Bottom Line
Happy 100th birthday, McKinsey. Our former employer.
A firm born in a Jazz Age accounting professor's imagination. Shaped by a perfectionist named Bower into the gold standard of professional services. Responsible for some of the most influential ideas in business history — from the barcode to the White House Chief of Staff to the modern CEO role — and some of the most consequential mistakes.
That's 100 years. Not a story of pure heroism. Not a story of pure villainy. A story of extraordinary impact — for better and for worse — wielded by some of the smartest people in the world, who sometimes forgot that being smart is not the same as being right.
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