Conservatives in America have, in recent months, used the idea of freedom to argue against wearing masks, oppose vaccine mandates, and justify storming the Capitol. They routinely refer to themselves as “freedom-loving Americans.” Freedom, as a cause, today belongs almost entirely to the right.

This was not always the case. In the early 1960s, civil-rights activists invoked freedom as the purpose of their struggle. Martin Luther King Jr. used the word equality once at the March on Washington, but he used the word freedom 20 times.

The conservative use of the idea of absolute freedom, of freedom as your personal property, to shift American politics to the right came shortly after King’s speech, and indeed was a direct reaction to his argument that one’s own freedom depended on everyone else’s. This wasn’t an organic response. Rather, conservative activists and business leaders designed an opposite idea of American freedom to protect their own interests. That effort can be seen in the role played by one of the most overlooked yet powerful forces in 20th-century America: the nation’s realtors.

In 1963, California, with half of the country’s realtors, passed a fair-housing law to limit housing discrimination. Realtors decided to fight back. They asked voters to approve a state constitutional amendment, Proposition 14, prohibiting the state and any municipality from ever limiting residential discrimination in any way.

Realtors had big incentives for maintaining segregation. Having invented it in the early 1900s as a marketing tool for selling homes, they had made segregation central to their business practices. They created racial covenants to exclude members of minority groups from new developments, existing neighborhoods, and entire cities and shaped federal redlining maps, all premised on the idea that anyone selling to minority families was destroying the future of all the neighbors. Any broker who did so was therefore destroying his future business. Despite the Supreme Court outlawing court enforcement of racial covenants in 1948, realtors used racial steering—such as lying to minority prospective buyers that a home had just been sold and controlling newspaper real-estate listings—so effectively that by the early ’60s, Black Americans were excluded from 98 percent of new homes and 95 percent of neighborhoods.