The suit was bitterly contested in court by Mayor Michael Bloomberg until a Brooklyn judge ruled in 2010 that the city had discriminated against black and Latino firefighter applicants by giving a written entrance exam that unfairly weeded out minorities.

The lawsuit and the disparate-impact ruling it produced ignited a powder keg of resentment and rage among many rank-and-file firefighters, known as New York’s Bravest. Many decried the “special treatment” given to blacks.

Few stopped to ask if the city was truly being well-served by following the civil-service hiring process—a system devised more than 100 years ago to break the corrupt grip of Tammany Hall’s Boss Tweed. Tweed leveraged waves of Irish Catholic immigrant voters into a powerful base by doling out city jobs. Even after the so-called “merit system” of Civil Service was imposed, his machine-made patronage dominated city hiring.

New York City, like many other municipal, state, and federal governments, has clung to the civil-service process of administering a standard written test for most of its city jobs. Some, like the FDNY and NYPD, also require rigorous physical exams and mental health and background checks. Candidates are ranked based on their scores and picked from a list—and in theory, it’s a level playing field that gives all applicants an equal chance.

Yet in practice, it’s never been quite as even-keeled as its proponents want people to believe. One of the FDNY’s first black firefighters, Wesley Williams, was hired in 1919 with an outstanding score on the written and a perfect score on the physical—only one other man in the department’s history could claim that. His character reference—something all candidates had to produce—was written by former U.S. president Theodore Roosevelt. And even then, the Tammany-controlled FDNY waitlisted him for as long as possible.

Williams did eventually get into the FDNY—only to confront behavior among some of his fellow Bravest that resembled the terrible bigotry of the Jim Crow south. By the end of the 1930s, under Tammany Mayor Jimmy Walker, there were only four African Americans in the FDNY—even as hundreds of thousands came north to look for work in the midst of the Great Depression. Many of them managed to find it in other city agencies in New York, but not among the Bravest. It took an overhaul of the civil-service system by incoming Mayor Fiorello LaGuardia in 1938 to break the de facto black lockout. But even as African Americans took 100 slots within the 6,000 strong department, they couldn’t achieve the same parity within the FDNY that they achieved in other parts of city government.

Women, too, were unable to break into the brotherhood in any meaningful way, despite a lawsuit brought by pioneer Brenda Berkman that in 1982 forced firehouse doors to open for 42 trailblazers. Three decades later, there are 46 women firefighters in the FDNY—and the department has only just moved to retro-fit its firehouses so the women have separate bathrooms.