It is natural to think there is something deeply unfree about work in the contemporary United States. Describing her job in an Amazon warehouse, journalist Emily Guendelsberger writes, “I walked up to sixteen miles a day to keep up with the rate at which I was supposed to pick orders. A GPS-enabled scanner tracked my movements and constantly informed me how many seconds I had left to complete my task.” A man employed at a different facility said he found pervasive surveillance and inhuman speed “so soul-sucking I found myself nearly crying in my car right before I was supposed to walk in.”

That feeling is connected to a real material fact about the workplace: one of the defining features of the employment relationship in all capitalist countries is that the worker’s will is, by law, “subordinate” to the employers. The employer has the right, within broad bounds, to define the nature of the task, who performs it, and how. This shows up in all kinds of surveillance, control, and submission — also known as maximizing productivity and extracting profit.

Just consider who controls one of the body’s most essential functions: going to the bathroom. Workers in the United States can be forced to urinate during employer-mandated drug testing; or forbidden from urinating if it isn’t break time. In Amazon warehouses, workers, whose every move is tracked, forego trips to the restroom to avoid being disciplined or fired for too much “time off task.” In a poultry-packing plant, employees were forced to wear diapers to work because they said they knew they would be let go if they demanded the bathroom breaks their bosses denied them. Employers control or seek to control many other aspects of workers’ lives, from their Facebook posts and political speech to the wages they earn and the rates at which they work.

It is no surprise, then, that there is a long history of comparing capitalist wage labor to chattel slavery.

In 1873, Ira Steward, son of abolitionists and founder of the eight-hours movement, looked out over the United States’ industrial sweatshops, its fourteen-hour days for poverty wages, and wrote, “Something of slavery still remains.” His point was not that wage labor and slavery were the same, but that, for all the talk of emancipation, many aspects of the employment relationship smacked more of servitude than of freedom.

By the time Steward wrote those words, the critique of wage slavery was at least fifty years old. In 1828, Thomas Skidmore, avowed critic of slavery and founder of the New York Working Men’s Party, wrote:

For he, in all countries is a slave, who must work more for another than that other must work for him. It does not matter how this state of things is brought about; whether the sword of victory hew down the liberty of the captive, and thus compel him to labor for his conqueror, or whether the sword of want extort our consent, as it were, to a voluntary slavery, through a denial to us of the materials of nature.

Fifteen years later, a Skidmore collaborator turned land reformer, George Henry Evans, found something of slavery in the poor, landless worker: “he must ask leave to live . . . he is liable to be driven away at the will of another.” When arguing against propertylessness and for the redistribution of land to all workers, Evans said, “The National Reform measures would not merely substitute one form of slavery for another, but would replace every form of slavery by entire freedom.”

Not everyone decrying wage slavery did so on egalitarian grounds. In the early republic, some racist white workers invoked wage slavery not to argue against chattel slavery and wage labor together but, instead, to maintain that white workers should not be reduced to the condition of black people. Theophilus Fisk, for instance, worried in the 1830s about “the white slaves of the North” but denounced abolition. Freedom was, for racist figures like Fisk, a racial privilege rather than a universal end. It was possible, then, to object to wage slavery as “white slavery” and to use the term to divide people by race, rather than to unite them in class struggle. But that was generally the less common use of the term.

After the Civil War, the critique of “wage slavery” really took off. A group I have elsewhere called “labor republicans” drew on and extended the earlier views of people like Skidmore and Evans to argue that capitalist labor relations failed to live up to their promise. Labor republicanism formed the guiding ideology of the Knights of Labor. Founded in 1869, the Knights were the first national labor association to organize relatively unskilled black workers together with whites on a mass basis — an effort not meaningfully duplicated in the United States for another fifty years. In 1886, their membership peaked at nearly 1 million workers, with everyone from predominantly white Northern shoemakers to Southern black cane-cutters carrying a Knights of Labor card.

In articles with titles like “Wages Slavery and Chattel Slavery,” the Knights argued that “the whole process of civilization has been to emancipate human beings from the condition of slavery in which they have been held by their fellow men . . . [however] civilization has not yet reached its highest point of development, nor can it develop much further without first having abolished wages slavery, for that form of slavery stands to-day as one of the greatest barriers to the progress of civilization.”

This “wage slavery,” the Knights contended, first appeared in the dependence of propertyless workers on their employers. Lacking any reasonable alternative but to look for a job, workers were in a structurally subordinate role. This made the labor contract something less than fully free. As George E. McNeill, one of the Knights’ leading figures, put it, in a labor contract, the workers “assent but they do not consent, they submit but they do not agree.”

Once at work, submission was the order of the day. “Is there a workshop where obedience is not demanded — not to the difficulties or qualities of the labor to be performed — but to the caprice of he who pays the wages of his servants?” asked one Knight. Another Knight complained, “Thus is sycophancy deified in our workshops . . . thus is abject servility ennobled, as it were, by bosses and foreman.”

They sought “to abolish as rapidly as possible, the wage system, substituting co-operation therefore,” by which they meant a national economy of interconnected worker-governed cooperatives and publicly owned utilities (such as railroads and schools). The vision appealed to everyone from Southern black agricultural workers to Anglo-American and immigrant workers in the North and the West, who joined under the Knights’ banner.

The Knights were not the only ones who thought something of slavery was to be found in so-called free labor. In 1865, former slaves who had appropriated land on Edisto Island wrote the Freedmen’s Bureau Commissioner: “We were promised Homesteads by the government” but the government was now in the process of returning all land to its previous owners — their former masters. Abolition, however, was not emancipation.

The federal government, they insisted, “now takes away from [us] all right to the soil [we] stand upon save such as [we] can get by again working for your late and [our] all time enemies.” Being thrown into the labor market was “not the condition of really freemen.” To be truly free, they demanded “land where we shall not be slaves nor compelled to work for those who would treat us as such.”

Frederick Douglass, arguing for unity among black and white laborers in 1883, said that “experience teaches us that there may be a slavery of wages only a little less galling and crushing in its effects than chattel slavery, and that this slavery of wages must go down with the other.”

The critique of wage slavery was then taken up by anarchists, socialists, and labor radicals of various stripes, who railed against the capitalist labor market and organized for a multiracial struggle against the owners of capital. Lucy Parsons, born a slave and later a widely known anarchist, declared in one of her most famous speeches:

How many of the wage class, as a class, are there who can avoid obeying the commands of the master (employing) class, as a class? Not many, are there? Then are you not slaves to the money power as much as were the black slaves to the Southern slaveholders? Then we ask you again: What are you going to do about it? You had the ballot then. Could you have voted away black slavery? You know you could not because the slaveholders would not hear of such a thing for the same reason you can’t vote yourselves out of wage-slavery.

We can find similar quotations from famous left-wing leaders like Emma Goldman, Eugene Debs, and Big Bill Haywood, and less famous figures, like Alexander Howat, Elizabeth Gurley Flynn, and Hubert Harrison.

For all these thinkers, three thoughts tended to go together. First, wage labor was wage slavery not because it was the same as chattel slavery but because it was shot through with its own forms of subservience and subjection. The project of emancipation was therefore unfinished. Second, the solution was to replace wage labor with some form of democratically managed “cooperative commonwealth.” Third, the demand for liberty could unite workers across race and gender in a project to seize control of the economy and turn it to collective purposes.

This was the holy trinity of the Left’s emancipatory program — one that guided millions in the nineteenth and twentieth century.