In the wealthy, all-white towns along the Connecticut Gold Coast, where blacks were effectively excluded from living by racist housing policies, local officials kept public spaces segregated by narrowing the definition of who constituted the public. While nearby urban black populations swelled and the demand for access to public places of recreation spiked, towns like Greenwich, Westport and Fairfield restricted their beaches to residents. It was obvious whom these laws were meant to exclude.

These wealthy enclaves were also among the first to use privatization as a means of segregation, a practice that would proliferate in the decades following the 1964 Civil Rights Act.

The Harlem Renaissance novelist Ann Petry once wrote that her “most humiliating Jim Crow experience” took place in Connecticut, where she grew up. She had gone on a trip to a beach with her Sunday school class. The beach was technically private, but that had never mattered — until Petry, the only “colored” girl in the group, came along. On this occasion, the children and their teacher were deemed trespassers and told by a guard, “If you don’t get off the beach, I’ll call up the sheriff.” The children were forced to have their picnic on the church lawn. “We ate,” Petry later wrote, “in a clammy silence.”

The civil rights icon Constance Baker Motley, who grew up in New Haven, Conn., in the 1930s, recalled accompanying two white teenage friends to a private beach in the neighboring town of Milford. Although Motley’s white friends were not members, they went there often. But with an African-American joining them, “there was suddenly a membership requirement.” The three returned to New Haven, Motley dripping in sweat and stewing in indignation, her white friends having learned an important Jim Crow lesson.

Most white Americans prefer to consign such naked acts of discrimination to a shameful past that we have supposedly overcome. But in light of these recent incidents, it would be more accurate to call the forms of Jim Crow that prevailed in the Northeast in the early- to mid-20th century the cutting edge in technologies of exclusion, a sign of things that were to come.

It will take more than sensitivity-training sessions and the public shaming of racist, hypervigilant white women to dismantle today’s system of segregation. Limiting the power of white people to use the law to act out their vision of a “quality” life that excludes black people is a place to start.