The historian Kim Phillips-Fein’s new book is published amid celebrations of the 250th anniversary of the declaration of independence and its truth “self-evident, that all men are created equal”. Country of Lords, however, is a history of Neo-Aristocrats, Social Darwinists, Tech Utopians, and the Long Fight Against Equality in America.

Concise and hard-hitting, the book arrives at a time of glaring social and economic inequality, Phillips-Fein seeing Elon Musk “emerging as a trillionaire very much on people’s minds, with a deep level of discomfort, both fear and anger about what this portends”.

“It’s always hard to know what’s going to be happening when you have written a book,” she said. “But I think those questions about economic equality and the impact of extreme levels of economic hierarchy and concentration, and the questions, ‘Can you still have a democracy any longer? What are the ways that you can counter that? What alternate visions are there if you want to live in a world that’s not characterized that way?’, are present.”

Phillips-Fein studies conservatism and “questions about capitalism and democracy”. Her first book, Invisible Hands, was a study of businessmen who fought the New Deal of the 1930s. Her second, Fear City, about the New York economic crisis of the 1970s, was a finalist for the Pulitzer prize. Hers is a major voice. It’s also unique. Not many books start with founder John Adams and end with Peter Thiel of Palantir, Musk’s fellow techno-fascist. Might such company seem unfair on Adams, the Boston lawyer who was part of a great revolution but feared what was unleashed?

“I hope this comes through,” Phillips-Fein said. “Adams is very different from [steel magnate] Andrew Carnegie and [Yale professor] William Graham Sumner and the late 19th-century social Darwinists, and the pro-slavery advocates. He’s also definitely very different from people who are saying extreme levels of economic inequality are good.” Adams, however, was “very ambivalent and skeptical of egalitarian claims … during and after the French Revolution: a deep sense of you can have too much egalitarianism.

“In his writing, he does also give a strong kind of conservative temperament and foundational sense of the problems of arguing for greater equality and a deep wariness and sense of pessimism about a politics that claims to do that.”

And so Adams takes his place in Country of Lords. Other subjects include preachers of race-based inequality from George Fitzhugh, a Confederate theorist of slavery as natural good, to Theodore Lothrop Stoddard, a hack journalist who had a huge bestseller in 1920 with The Rising Tide of Color Against White World-Supremacy, “part of a larger intellectual subculture of ‘scientific’ racism … in the aftermath of world war one”. There is also Carnegie, the Scottish-born tycoon who flourished in the Gilded Age of the late 19th century.

“What makes Carnegie so interesting is that he at least allows himself to have some sense of ambivalence,” Phillips-Fein said. “He says that while the concentration of wealth is absolutely necessary and inevitable, and the people at the top … should have the ultimate say over resources, he is deeply aware that this is politically dangerous, that … it creates an unstable society in which the poor and the working class might actually hate the wealthy, and that’s not in the interest of the wealthy in the long run. Also, he has a sense that human brotherhood is lost, or some kind of community that had existed.”

Carnegie’s father was a Chartist, seeking working-class rights. Carnegie’s major outlet for doubts about his wealth came through philanthropy, prominently the construction of libraries for working people.

“He had a very deep sense of paternalism,” Phillips-Fein said. “He was very invested in the idea of business as a romance and kind of a space of adventure and conquest and feudal benevolence. I think Carnegie’s answer was ultimately that the wealthy should have their money but they shouldn’t bequeath much to their descendants, they should invest it in massive philanthropic projects, and this was better than raising wages or other things like that … It is his level of guilt and ambivalence that I think does make him appealing, if also troubling. I think it raises a set of questions that he certainly was never really able to resolve.”

The 1892 Carnegie Steel strike and its violent suppression devastated Homestead, Pennsylvania, and left Carnegie disillusioned. Now, in Washington, Carnegie Science is the Qatari embassy. At Mount Vernon, the Carnegie library hosts an Apple Store.

Country of Lords is also a primer on modern inequality. In the early 1900s, Henry Ford mixed mass auto production with vicious racism. In mid-century, William Shockley was a proto-tech mogul “who went completely off the rails”.

“He was a co-inventor of the transistor and he figures in different histories of Silicon Valley because he ran this company and wanted to maintain a tremendous amount of control, and as a result a bunch of the employees quit and founded their own firm [two eventually founding Intel] … So after Shockley Labs fell apart, Shockley started to become drawn to racist science, pseudoscience and IQ testing in particular. I don’t think anybody really knows exactly what triggered this, but he starts to talk a lot about it publicly in the mid-60s. He was at Stanford at the time. He was supposed to be teaching physics and engineering.”

Shockley, Phillips-Fein says, was really “a uniquely horrible person, and probably quite unhappy as well.” If that sounds familiar, also like Musk, Shockley wasn’t unique. Linked to the meritocratic movement of the mid-century, he was “not isolated. He is actually part of what is a growing, troubling community of people who coalesce in the late 60s, early 70s, and who are really responding, not always directly, to the context of the civil rights movement.

“It was obviously focused on overturning racist legislation that undergirded segregation, but it also made claims about the distribution of resources, saying the reasons for Black poverty are not innate, they reflect centuries of legal and political structures that have upheld white wealth and laid the foundation for exploitation of Black workers and working-class people, and the political disfranchisement has resulted in this distribution of resources. In other words, that’s nothing to do with merit at all.”

In such soil, Phillips-Fein finds the roots of “the tech titans of today”, rejecting liberal ideals.

“They are very skeptical and hostile towards elite institutions, or at least, have a very broad relationship to them,” she said. “So Peter Thiel embraces this set of ideas about competition drawn from the economist Joseph Schumpeter. He writes about how companies in a normal marketplace are competing at the margins … but every so often someone will come along and create a new invention, usually that winds up dominating the marketplace and changing it, and whoever does that first will completely change the marketplace.

“Thiel has the same idea. He kind of writes about how, ‘I was growing up, I wanted to be the best, I wanted to go to these elite institutions. I went to law school, I had the straight and narrow path, but then I realized that all that was wrong, and actually you had to disrupt everything, create your own monopoly, a monopoly of one: nobody else can ever be you,’ and then the people who are kind of blessed with this genius to recognize how to create something completely new in the world, those are the people who will deserve to win in this race and deserve to command the resources of society.”

The Country of Lords endures.

• Country of Lords, published by WW Norton & Company, is out now