Forty-two years ago, the Supreme Court issued its landmark Roe v. Wade decision, which legalized a woman's right to abortion. Ever since, America has debated and grappled with how to regulate a woman's right to choose. These graphs and charts help provide some context of how abortion access has changed in the United States since Roe, and how America's position on the issue has evolved over four decades.

1) The abortion rate is at a 40-year low

The abortion rate in the United States rose steadily during the 1970s, shortly after the Roe decision. It peaked in 1980, at 29.3 abortions per 1,000 women between the ages of 15 and 44 — and has been falling ever since. In 2011, the most recent year for which data is available, it hit 16.9 abortions per 1,000 reproductive age women — lower than any rate recorded since 1973. There were 1.3 million abortions in 1981, compared with 765,651 abortions in 2010.

Why is the abortion so low? Part of it probably has to do with the fact that fewer teenagers are getting pregnant in the first place — although why that's happening is also a bit of a mystery. And states have also gotten more aggressive at regulating abortion, although the research on whether those laws actually stop women from terminating pregnancies is mixed.

2) There are fewer abortion providers in America than any other time since Roe

The number of abortion providers in the United States decreased by 38 percent between its peak, in 1982, and 2005, according to the Guttmacher Institute. This fall has coincided with the decline in the abortion rate, and also a wave of violence against abortion providers in the 1980s and 1990s which left five doctors dead and many more facing threats.

Abortion doctors today will often talk about the precautions they take against violence in their work. "I'm mindful of my circumstances," Willie Parker, Mississippi's only abortion doctor, told me earlier this year. "I lock my car. I have contact with law enforcement, in terms of reaching out if I need to. I don't carry a gun, but I'm prepared to defend myself."

3) The women who get abortions are disproportionately young, minority and already mothers

The majority of women obtaining abortions — 58 percent — are in their 20s, according to a 2010 report from the Guttmacher Institute, a non-profit that conducts research on reproductive health and is supportive of abortion rights. The same report found that non-Hispanic white women account for 36 percent of abortions, black women for 30 percent, and Hispanic women for 25 percent.

Forty-two percent of women having abortions in 2008 were poor. This was a significantly larger proportion than in 2000, the last time of the survey, which showed 27 percent of abortion patients to be low-income.

The same report found 85 percent of abortion patients to be unmarried (including 29 percent who were cohabiting with their partner). About 60 percent of women having abortions already have one child. That includes 34 percent who already had two or more children.

4) Public opinion on abortion isn't as split as you think

Public opinion polls have, for decades now, shown a split between Americans who identify as pro-choice and pro-life. The number of Americans identifying as pro-life has grown since the 1990s, as this Gallup chart shows:

But those labels don't quite capture the nuance to Americans opinions about when its ok terminate a pregnancy. There is another Gallup poll that asked about whether abortion should be legal at different points in the pregnancy. There, you see much more solid majorities: most Americans think that abortion should be legal during the first three months of pregnancy and illegal during the last trimester:

5) States passed more abortion restrictions between 2010 and 2014 than they did in the prior decade

The Roe decision did create a legal right to abortion across America. But further Supreme Court decisions have allowed states to restrict that right, so long as those restrictions do not create an "undue burden" on women seeking to terminate a pregnancy.

In the early part of this decade, states passed an unprecedented number of restrictions: 231 in the course of three years.

A handful of factors help explain the surge in abortion restrictions that began in 2011. Republicans gained control of many state legislatures during the 2010 midterms, making it easier to pass some of the abortion restrictions that had previously failed to garner enough political support.

The Affordable Care Act likely played a role too, as it catalyzed a national debate over whether government-subsidized health insurance plans would pay for abortions. Many of the abortion laws passed since 2011 target this exact issue; 25 states now restrict abortion coverage in plans offered in the new health insurance exchanges.

Last, other abortion laws were gaining traction around the same time. There's been an increasingly successful campaign to ban later-term abortions, a movement that began when Nebraska passed a 2010 law barring pregnancy terminations after 20 weeks. Twelve states now have such bans on the books, although Arizona's was recently ruled unconstitutional.

When one state has success with an abortion restriction, whether its a ban at 20-weeks or restricting coverage on the exchanges, other states will often follow. The pro-life movement has an infrastructure to support this kind of collaboration: Americans United for Life will often write model bills that legislators in other states can use to introduce a particular type of restriction. That type of infrastructure makes it easier for one idea to spread through different state legislatures, and increase the number of restrictions on the books.

6) Every state except Oregon now restricts abortion access in some way

Conservative states tend to pass more abortion restrictions than liberal states. But even deep blue areas of the country, like the Northeast or West Coast, tend to place at least some limits on abortion. This chart from Remapping the Debate shows that every state except for Oregon has at least one law on the books that regulates the issue:

You can see a full, interactive version of that graphic here.

Correction: An initial version of this story misstated when the abortion rate hit an all-time low. It is at a 40-year low.