In the final confrontation, there are always a little more than a dozen outliers, states needing a nudge — or maybe a shove — toward the next civil rights milestone.

When the Supreme Court struck down segregated education in 1954, 17 states still had laws legally requiring schools to separate black and white children. When the court struck down anti-miscegenation laws a decade later, it was still illegal in 16 states for blacks and whites to marry. When the court dealt a final blow in 2003 to sodomy laws, 14 states still had them. This year, as the court prepares to take up gay marriage, with Alabama in the throes of what feels like a last-ditch stand-off, 13 states remain closed as of today to gays who wish to wed.

This is the recurring history of civil rights progress: early adopters, halting progress — through lower-court rulings or popular vote — then finally a mandate for the unwilling. If every civil rights movement has a frontier, it also has a rear.

Below, we've mapped those states at each of these moments when the Supreme Court has stepped in to settle arising civil rights for those corners of the country still opposed to granting them. Again and again, a court historically wary of getting too far out ahead of the nation on social change has asserted itself when opposing states — but not necessarily opposing public opinion — had become a notable minority. Alabama, which seems to be reasserting an old reputation today, reappears in many of these maps. But the outliers are not always the same. Only four states — Texas, Louisiana, Missouri and Mississippi — appear on all four maps.

When the Supreme Court struck down segregated schools in 1954 in Brown v. Board of Education, states had a range of policies on the question, some banning segregation, some permitting it, some outright requiring it. The states shown above all required segregation in public schools. Four others, New Mexico, Arizona, Kansas and Wyoming, additionally permitted it in some form.

Parallels to today's gay-marriage fight are most often drawn to the 1967 Loving v. Virginia decision, which struck down laws in 16 states prohibiting or punishing interracial marriage. One significant difference this time is that public opinion much more broadly supports gay marriage today than it did interracial marriage 50 years ago.

In 2003, the Supreme Court struck down a sodomy law in Texas that criminalized private sexual activity between gays and lesbians. The 6-3 ruling, in Lawrence v. Texas, made such laws unconstitutional in 13 other states as well.

Although individual probate judges — and the state's chief justice — are defying the order in Alabama, a federal judge has ruled that gay marriages can begin in the state as of today, making Alabama one of 37 states where such unions are legal. And so Alabama does not appear on the above map. In most of the remaining states, courts have ruled on existing gay marriage bans (either upholding or striking them down), but those states are now waiting for the Supreme Court to step in. Much of the progress shown above has come not through ballot initiatives and state laws, but through court rulings.