Florida is a state of stark contrasts. Travel a few miles from the opulent mansions of Miami Beach and you reach desperately poor neighborhoods. There’s the grinding poverty of sugar cane country and the growing middle class of Jacksonville. All told, half the public-school students in Florida qualify for subsidized lunches. Many are the first in their families to speak English or contemplate attending college.

In many states, those economic differences are reflected in the classroom, with students in wealthy schools taking many more advanced courses.

But not in Florida. A ProPublica analysis of previously unreleased federal data shows that Florida leads the nation in the percentage of high-school students enrolled in high-level classes—Advanced Placement and advanced math. That  holds true across rich and poor districts.

Studies repeatedly have shown that students who take advanced classes have greater chances of attending and succeeding in college.

Our analysis identifies several states that, like Florida, have leveled the field and now offer rich and poor students roughly equal access to high-level courses.

In Kansas, Maryland and Oklahoma, by contrast, such opportunities are far less available in districts with poorer families.

That disparity is part of what experts call the “opportunity gap.”

“The opportunity to learn—the necessary resources, the curriculum opportunities, the quality teachers—that affluent students have, is what determines what people can do in life,” said Linda Darling-Hammond, a professor of education at Stanford University.

Our analysis offers the first nationwide picture of exactly which advanced courses are being taken at which schools and districts across the country. Previous studies and surveys have tracked some of these courses, but never with so many variables and covering so many schools. (More than three-quarters of all public-school children are represented in our analysis. Check out our methodology.)

We have also created an interactive feature so you can search for your school and see how it compares, for example, with poorer and wealthier schools nearby. It also shows the percentage of inexperienced teachers in schools. Here’s Beverly Hills High compared to a much poorer school in Southern California. And here’s a stark example from New Jersey.

The analysis was drawn from a nationwide survey by the Department of Education’s Office for Civil Rights, which collected school-by-school reports on a range of offerings, including physics, chemistry and Advanced Placement courses in high schools. The department did the survey to assess whether states and other localities are discriminating by race, gender or disability. State and local education administrators, of course, are responsible for most funding and policy decisions.

We compared the survey results to poverty levels. (We measured that by looking at the percentage of students who receive free- or reduced-price lunch—which the government offers to students from low-income families.)

While our analysis found a link between race and lack of access, poverty was the predominant factor in determining the proportion of students in a school or district who were enrolled in higher-level instruction.

The department plans to make public additional data in the coming months on graduation rates and test scores for these schools. When it does so, we will publish additional stories pinpointing the states in which equal access has achieved the desired results and where it has not.

From the data released so far, Florida stands out. Its results follow a decade-long initiative to broaden educational opportunity launched by then-governor Jeb Bush and his Education Commissioner, and now fellow former governor, Charlie Crist.

“The fact that some states have eliminated these disparities proves that if we make this a priority of policy it can be done,” said Pedro A. Noguera, an education professor at New York University.

Other states show just how complex the problem is. While Maryland has been celebrated for the high percentage of students taking advanced classes, our analysis shows enrollment in such classes at high-poverty schools is much lower. Or take Mississippi: Richer and poorer schools there provide roughly equal access, but that masks the reality that very few students are enrolled in the classes overall. A Maryland official said enrollment of low-income students has been increasing recently, while a spokesman from Mississippi’s department of education was not immediately available for comment.

While most experts agree about the value of giving students expanded opportunities, many caution that offering advanced classes is not a solution on its own to deeper-rooted gaps in preparation and achievement. They say students often need additional support.

“We’re making AP a reform strategy in and of itself,” said Kristin Klopfenstein, director of the Education Innovation Institute at the University of Northern Colorado. “When it comes to a struggling turnaround school, why in the world would you think that somehow plunking down an AP program would improve that school?”

But with the right support, even the most disadvantaged students can thrive, according to Jose Huerta, the principal at Garfield High School in East Los Angeles.

The school was the basis for the 1980’s classic, Stand and Deliver, the story of a determined high-school math teacher, Jaime Escalante, whose single-minded conviction that kids from poor and minority backgrounds could succeed, led to many of his students passing the demanding Advanced Placement calculus exam.

Garfield still provides many rigorous courses—with extra help for some students. And Huerta said that this year his students are heading to colleges such as Yale, Brown and Harvard.

“This is an extremely poor area. These are kids whose parents can’t speak the language, and they’re going to the top college in the country,” said Huerta. “We raise the bar and our kids are going above it.”

How Did Florida Do It?

Florida’s schools once mirrored the inequalities seen in many other states. In 2003, the NAACP sued the state, arguing that it had an “unequal education system.”

“A decade ago, few minority students were taking PSAT/PLAN tests of AP courses, and even fewer were going to college,” said former Gov. Jeb Bush, via email, referring to testing programs that have been used to predict which students will succeed in AP courses. “Florida schools and teachers were not incentivized to provide or teach AP courses—particularly in low-performing schools,” he said.

Bush introduced a combination of measures to foster AP courses, including a partnership with the College Board, the national nonprofit group that manages AP courses and exams. The partnership kicked off in 2000 and was later written into state law. Its stated goal was to “prepare, inspire, and connect students to postsecondary success and opportunity, with a particular focus on minority students and students who are underrepresented in postsecondary education.”

As part of the program, the College Board is now focusing on schools in rural districts, such as Okeechobee in central Florida, where students are often the first members of their families to seriously contemplate attending college, according to Toni Wiersma, principal of Okeechobee High School.

“We fight against the old perception that some people are just not college material,” said Wiersma. “We want to make sure that every student is prepared to do what they want to do.”

The question remains: Have these changes improved student performance?

While measuring outcomes in education is notoriously difficult, data show that the numbers of high-school seniors from poor families who pass at least one AP exam have surged. In 2006, students from low-income families made up 10 percent of all seniors who passed an exam. By 2010, that percentage had doubled.

Florida students still perform below the national average on standardized tests. Still, other government studies show that Florida has made greater strides in closing the achievement gap between white and minority students than many other states.

Florida, Bush said, is setting an example for other states.

“If Florida ... can do it, every state can.”

Kansas’ Long History of Unequal Access to Education Continues

Kansas has also tried to improve, but it still has some of the largest opportunity gaps in the nation.

Few states have as deep a history with educational inequality as Kansas. The state was the birthplace of the landmark civil rights decision Brown v. Board of Education of Topeka, in which the U.S. Supreme Court ruled that segregated schools were inherently discriminatory and that states must make education “available to all on equal terms.”

Nearly 60 years later, Kansas still has a deeply unequal educational system, according to the data. High-poverty schools still tend to have fewer students enrolled in AP courses, advanced math, chemistry and physics. Like AP, these courses have been linked to later academic success.

“When people in middle America look at this input data and realize that we’re never giving kids a shot in the first place, that American value of fundamental fairness starts kicking in,” said Russlynn Ali, head of the Education Department’s Office for Civil Rights, which conducted the survey.

Officials from the Kansas Department of Education disputed the finding that the state is giving unequal treatment to poorer children. They pointed out that the state has set aside extra funds for schools with high numbers of students from low-income households.

“The funding gives additional weighting to every child that qualifies for free lunches,” said Brad Neuenswander, deputy commissioner at the Kansas State Department of Education. “The poorer your district, the more financial resources you receive.”

College Board data show that these efforts may have had some effect. The percentage of AP test-takers who are from poor families has doubled over the past four years. However, the numbers are still low.

Neuenswander said many districts choose to send students into community colleges, rather than enrolling them in advanced placement courses, particularly those students who were more interested in pursuing a trade.

“We’re a rural state, but more than that, we are heavy agriculture as well as air manufacturing and technology,” he said. Several major companies, such as Boeing and Sprint, have locations in Kansas, which offer employment opportunities to local students, Neuenswander said. “A lot of our students don’t go on to a regent university. They go on to vocational and technical colleges, because of the good jobs here that require skills and trades.”

But nearly 60 years after Brown v. Board of Education, another lawsuit is winding its way through the Kansas court system, claiming that inadequate funding is having a disproportionate effect on the state’s neediest students.

It follows at least six previous cases in the state that have made similar claims.

The plaintiffs in the new case include children across the state who need extra support, said Alan L. Rupe, the lead attorney in the class action suit and an expert in education funding litigation.

“Kids with special needs—whether they’re English-second-language, disabled kids, immigrants or minorities—those kids cost more to educate,” Rupe said. “When funding is reduced, those kids are hurt the most.”

Rupe said one of the most glaring inequalities between rich and poor districts was the ability to attract and retain talented and experienced teachers.

“If you’re a teacher making $35,000 in Kansas City, in a classroom that’s got 90 percent free and reduced-price lunch, and you have the opportunity to drive 10 miles to teach at a brand new school in a neighboring county, to teach in a smaller class, to earn more money, you’re going to do it every time,” said Rupe. “And they do it every time.”

ProPublica intern Sergio Hernandez contributed reporting to this story.