Two summers ago, Indigo Williams couldn’t have been more thrilled to send her son off for his first day of school.

Her home was zoned into Madison Station elementary school in Madison, Mississippi, an “A” rated school and district where her son JS, then five, quickly dove into Kindergarten with enthusiasm. JS was taking Taekwondo lessons and was served fresh fruits and vegetables in the cafeteria. He had access to tutoring.

But when Williams and her children moved just a few miles away before the start of the following school year, her home was instead zoned to an elementary school in the Jackson, MS school district. She was horrified to see just how dramatic the difference could be.

Now attending Raines Elementary, Williams says JS’s environment “feels more like a jail than a school. Paint is chipping off the walls. They’ve served him expired food in the cafeteria,” she said.

“There are no extracurricular activities available for my son, no art or music class or even afterschool tutoring. There are not enough textbooks for him to take home or even for students to use in the classrooms, and the books that are in the classroom are outdated,” Williams added.

She worries that JS is growing bored with his classwork, and that the school doesn’t have the resources to challenge him or make learning interesting. “I’m afraid he’s falling behind other kids in better schools,” Williams said.

But Williams hasn’t just sat by and watched as her son’s quality of education deteriorated. She – and three other black Mississippi mothers – have put themselves and their young children at the centre of a lawsuit that argues the state has reneged on 150 year-old promise to offer a “uniform system of free public schools”.

The lawsuit, filed by Southern Poverty Law Center on behalf of the mothers, is about quality of education, but there is also a broader context reflected in the make-up of the student population in the two schools that JS has attended. The pupils at Raines School pupils are 99% black. The pupils at Madison Station school are 70% white. And in a state where, in the years after Brown v Board, the landmark 1954 US Supreme Court decision that outlawed segregation in schools, public officials in Mississippi considered shutting down public schools all together to avoid integration, race is never far from view.

“This case is about quality of education and making sure that quality is uniform no matter what color your skin is or where you live,” said Will Bardwell, an attorney for SPLC. “Mississippi gutted education rights over years and years to avoid integration, to the extent that they are now non-existent. We want to change that.”

Mississippi Goddam

By virtually any metric you choose, Mississippi has among the worst education systems in the US. In a July study, researchers using a 13-point quality rubric ranked the state 49 out of the 50 states and Washington DC.

Mississippi is also, by both median income and poverty level, the poorest state in the country.

This is no coincidence, of course. Because US public school are almost exclusively funded by state and local tax dollars, the amount of resources any given school has is almost wholly a function of how wealthy the people who live nearby are.

The Madison Station elementary school where JS began his student career is, by car, about 20 minutes north of Raines – but it isa universe apart. Elaborate gated mansions with circular driveways dot the road to the school which passes through expansive stretches of verdant green Mississippi pasture. Near the end of the school day, a fleet of immaculate saffron and black buses pull up to the building.

The environment mirrors the performance. In 2010 Madison Station was a National Blue Ribbon School, a Department of Education designation made to high performing schools. Some 72.6% of students are proficient in reading and 70.5% are proficient in math – well above the state average. In 2013, less than 9% of the school’s teachers were in their first year of teaching.

Down the road at Raines, 20% of teachers are in their first year. Only 11% of students are proficient in reading and just 4% in math.

The stark difference in racial makeup of the student populations is nothing new in the US of course, and nothing particularly specific to Mississippi. US schools are, on balance, more segregated today than they were 45 years ago.

JS (left) is now going to Raines elementary, where ‘the classrooms are too small for the number of students they put in them’. Photograph: Roy Adkins/SPLC

“Resegregation is not a Mississippi specific problem. It’s a nationwide problem, and that’s part of the reason this case isn’t really about segregation. It’s more about disuniformity,” Bardwell said.

The suit itself never actually mentions the term “segregation” and instead zeroes in on the language enshrined in the state’s first constitution, ratified in 1869, and approved by the US congress:

“It shall be the duty of the legislature to encourage by all suitable means the promotion of intellectual scientific moral and agricultural improvement by establishing a uniform system of free public schools by taxation or otherwise for all children between the ages of five and 21 years.”

That was then. But this bold promise of “uniform” compulsory education is no longer a part of the state’s constitution. The language has been progressively eroded in each of four updates over the ensuing 120 years. The most recent revision in 1987 has no mention of any commitment to a “uniform” quality of education – instead it promises “the establishment, maintenance and support of free public schools upon such conditions and limitations as the Legislature may prescribe”.

In other words, the promise amounts to virtually nothing – when it comes to education, the state legislature can do literally whatever it wants, so long as there are some free public schools.

This change to the language – and the nature of the promise the state makes about education – is at the heart of the suit and goes to the core of Mississippi’s troubled racial history and its relationship to the union. Concerned that the former Confederate territory would pass one type of constitution to reenter the union, and then modify it to deny rights to black Americans as time went on, the US congress passed the Mississippi Readmission Act. This was passed specifically to target any prospect that Mississippi would slip-slide on its obligations to its non-white residents once it had reentered the union. The readmission act, which technically remains federal law, states that:

“The constitution of Mississippi shall never be so amended or changed as to deprive any citizen or class of citizens of the United States of the school rights and privileges secured by the constitution of said State.”

Bardwell says that, insofar as the state once guaranteed uniform schools, and now does not, it has been in violation of the Readmission act.

“The point that we have made in this lawsuit is that regardless of the racial composition of your school is, federal law required Mississippi to provide the same opportunity at every school and that’s just not happening.”

And if the historical record is clear about one thing, it’s that the changes to Mississippi’s constitution after readmission were intended to do one thing: disenfranchise the state’s black citizens. “There is no reason to equivocate or lie about the matter,” said former Mississippi governor James Vardaman of the 1890 constitutional convention that amended the constitution and first modified the educational guarantees. “It was held for no other purpose than to eliminate the nigger from politics.”

He would know. Vardaman was one of the authors of the modified language, and those remarks were hardly out of character. On another occasion he opined blithely the “best way to control the nigger is to whip him when he does not obey without it”.

Black disenfranchisement was so effective in post-reconstruction Mississippi that Vardaman and his white supremacy ideology ascended to the state’s highest office during a century-long period where black Mississippians substantially outnumbered white ones. The state remains the one with the highest concentration of black Americans today.

The state also endures with the unofficial reputation as the nation’s most racist. It has some claims to that title. It was here that 14-year-old Emmett Till was murdered for the imagined crime of hitting on a white woman in 1955. It was here that civil rights icon Medgar Evers was martyred in his own driveway in 1963, and it was here that, one year later, during the Mississippi Freedom Summer campaign, activists James Chaney, Andrew Goodman & Michael Schwerner were murdered for the offense of registering black people to vote. The state’s preeminence in racial violence was perhaps most viscerally captured in Nina Simone’s 1964 tune, Mississippi Goddamn. Throughout the civil rights movement the state became the embodiment of white supremacy resistance.

‘A quality teacher in every classroom’

Precious Hughes and her children. Photograph: Roy Adkins/SPLC

Raines elementary is tucked in a residential stretch on the northwestern side of Jackson’s outskirts. There are no mansions here, but instead, humble L-shaped bungalows in various states of maintenance and disrepair. The school’s interior has the look of a place where educators and staff do what they can with what little they have. The floors are sparkling clean but on the corners they show the telltale decay of repetitive flood damage. On the wall, a colorful sign with construction-paper butterflies encourages students that “learning is an adventure”, sitting below ceiling tiles that are all discolored and crumbling on their edges.

“The school building is old, dark, and gloomy,” said Precious Hughes, the mother of a first-grader and a kindergartener at Raines. “The children are always bumping into each other because the classrooms are too small for the number of students they put in them.”

Real estate database Zillow rates the school as a one out of 10. School ranking website Schooldigger rates it as a zero out of five, and the 25th worst elementary school in the state.

And that type of performance is characteristic of predominantly black schools throughout the state. In Mississippi schools where the student body is at least 70% black, the average rating is D, for schools where the student body is at least 70% white, that slides up to a B.

Hughes said her oldest daughter, six, is in the majority of Raines pupils who struggle with reading. “Early on, Raines offered the Read Well program to help students boost their reading skills. That helped my daughter tremendously and improved her reading scores. But the program was shut down because there was not enough funding to pay for it,” Hughes said.

Hughes and Williams both also worry about overall teacher quality. One in five at Raines are in their first year of teaching, compared with one in 11 at Madison Station.

“The rubber meets the road at a quality teacher in every classroom,” said Tom Taylor, assistant superintendent of schools in nearby Yazoo County. “If that could ever be provided to every child in the state, or this nation for that matter, then that’s where you begin to see the progress.”

The way it’s been for a long time in Mississippi

The latest twist in the lawsuit is that the state filed a motion to dismiss it in July and released a statement calling the suit “cynical and misguided”, accusing Bardwell and the SPLC of an attempt “to fundraise on the backs of Mississippi taxpayers”.

Among their arguments for dismissal, the state said that even if you grant that the state were in violation of the Readmission act, the legal question would be whether the state should lose representation in Congress rather than one about how the state educates students.

“Of course, Mississippi has continued to be admitted to representation in Congress for nearly 150 years after the Readmission Act, [and] 127 years after the 1890 amendments to the State Constitution,” the motion notes.

Bardwell finds that response underwhelming. “The fact that this is the way it’s been for a long time in Mississippi doesn’t settle the question,” he said.

The state also argued that student performance might have nothing to do with state policies or funding levels at all, accusing the plaintiffs of ignoring the “many other factors that contribute to literacy and education – such as resources, parental involvement, medical problems, intellectual limitations, domestic violence [and] trauma.”

Bardwell called this argument “outrageous” and said the the four mothers in this suit were “doing everything they can” to see their kids succeed in school.

“I would defy anyone with the state of Mississippi to sit down with these parents, talk to them and come away with the impression that those parents are not,” Bardwell said.

“Just like every other parent in this state, I love my child,” Hughes said. “I know she deserves better, and that is why I’m filing this lawsuit.”