Our Explainer series digs into complicated topics our users are passionate about and ask questions that get to the heart of the issue, making us all better informed to create change.

At the 2015 Academy Awards, Patricia Arquette won a Best Supporting Actress Oscar for her role in Boyhood. Thanking her colleagues, friends, and family in her acceptance speech, she surprised the audience by closing with an impassioned plea:

“It’s our time to have wage equality once and for all and equal rights for women in the United States of America.”

Her speech was met by cheers from the audience and show of solidarity from Meryl Streep and Jennifer Lopez.

On the one year anniversary of that moment, Arquette is launching a campaign to make those words a reality. She’s started a petition calling on Congress and the Governors around the US to pass the Equal Rights Amendment.

You’ve probably heard of the Equal Rights Amendment, most commonly referred to as the ERA. It’s an amendment to the Constitution that some feminist advocates have been trying to pass for decades (literally). But we thought we could all use a refresher on this piece of legislation as Arquette brings new attention to it.

Everything you need to know about the ERA:

What is the Equal Rights Amendment?

The ERA is a proposed amendment to the US constitution that would ensure gender equality under the law. There is currently no federal legislation in the US that confirms this right.

There are three sections in the ERA:

Section 1: Women shall have equal rights in the United States and every place subject to its jurisdiction. Equality of rights under the law shall not be denied or abridged by the United States or by any State on account of sex.

Section 2: Congress and the several States shall have the power to enforce, by appropriate legislation, the provisions of this article.

Section 3: This amendment shall take effect two years after the date of ratification.

Why do people think the ERA is necessary?

The ERA is all about protecting people from gender discrimination. While we have certain laws that protect against this, they are easily rolled back. A Constitutional amendment solidifies and expands that equality and ensures that it cannot be revoked.

As The Feminist Majority explains it, the ERA would ensure that “those fighting sex discrimination would no longer have to prove discrimination, but instead those who discriminate would have to prove that they did not violate the Constitution.”

I seem to remember something about the ERA being controversial. What’s that about?

In the 1970s, there was a very public battle over the ERA that was led by a woman named Phyllis Schlafly, who launched a campaign called Stop ERA. She often spoke of the ERA as upending traditional gender roles, and focused on the possibility that the ERA could make women eligible for the draft (which was top of mind because of the Vietnam War).

Today, groups opposed to the ERA touch on some similar points. When the amendment was going through the Illinois legislature for ratification in 2014, The Illinois Family Institute contended that the ERA would “force women into military combat, invalidate privacy protections for bathrooms and locker rooms, undermine child support judgments, and jeopardize social payments to widows.”

Other groups believe that sex discrimination is covered by current Amendments, legislation, and case law and an amendment isn’t necessary.

Right, I would think women were taken care of by the 14th amendment?

The 14th Amendment was ratified in 1868 to address race discrimination but does not specifically address sex discrimination. Women were not granted the right to vote for 70 years after the passage of the 14th Amendment.

And it was another 50 years after that before the 14th Amendment was applied to a case in order to prohibit gender discrimination, according toequalrightsamendment.org. Still, in that and subsequent cases, the Court would decline to use the 14th Amendment in gender discrimination cases.

Justice Antonin Scalia emphasized the idea that the 14th Amendment does not cover gender in an interview with the California Lawyer when he said, “Certainly the Constitution does not require discrimination on the basis of sex. The only issue is whether it prohibits it. It doesn’t.”

I’m still not sure why legislation such as the Equal Pay Act, the Pregnancy Discrimination Act, Title IX, and case law don’t protect against gender discrimination?

There have been many laws and cases that have advanced the cause of gender equality. And they do offer some protections. Again, the concern is that legislation can be changed or repealed. So too can case law be overturned.

During a National Press Club event in 2014, Justice Ruth Bader Ginsburg said that if she could choose an amendment to add to the Constitution, it would be the Equal Rights Amendment.

She continued, “I think we have achieved [equal rights] through legislation, but legislation can be repealed, it can be altered. So I would like my granddaughters, when they pick up the Constitution, to see that notion – that women and men are persons of equal stature – I’d like them to see that is a basic principle of our society.”

How would the ERA affect other women’s rights issues?

There are many areas — everything from pregnancy and insurance discrimination to military policy — where a lack of Constitutionally guaranteed equal rights, negatively affects women.

Let’s look at one that is discussed a lot these days: equal pay.

Women working full time in the United States typically were paid just 78% of what men were paid, according to The White House. And the gap is even greater for African-American and Latina women.

“The ERA could help move pay equity legislation that has been stuck in Congress for several years and provides a more effective tool for sex -based employment discrimination litigation,” according to National Organization for Women (NOW). “It may also exert a positive influence in helping to raise pay…”

And what about reproductive rights?

Well, opinion is split over how the ERA would affect reproductive rights. NOW thinks, however, that the ERA could potentially nullify laws restricting access to contraception or abortion care since denying women medical care would be considered discriminatory.

What needs to happen for the ERA to become an amendment to the Constitution?

The bill will need to pass by a 2/3rd majority in the House of Representatives and the Senate. Once it passes, 3/4ths of the states (that’s 38) have to ratify it. Then it is made part of the Constitution.

When was the ERA first introduced to Congress?

Believe it or not, the ERA was written in 1923 (93 years ago!) by Alice Paul. If you dust off your history book, you’ll remember that Alice Paul was a leader of the woman suffrage movement, which had been successful in passing the 19th Amendment in 1920.

The amendment was first introduced in Congress in the same year and then introduced to every session of Congress for nearly 50 years.

What happened after 50 years?

The ERA was passed by the House of Representatives and Senate in 1972. States had until 1979 to ratify it, but only 35 of the mandatory 38 ever did. The deadline was then extended until 1982, but no more states ratified it. Since 1982, the ERA has been reintroduced in every session of Congress.

Has the ERA been introduced in the current Congress?

Bills have been introduced during the 114th Congress (currently sitting) in both the House and the Senate.

Senate Resolution 16 and House Resolution 52 were introduced by Sen. Robert Menendez and Rep. Carolyn Maloney, respectively. These bills would restart the traditional process, requiring passage of the ERA by Congress, then ratification by state legislatures.

Sen. Benjamin Cardin and Rep. Jackie Speier also introduced bills in the Senate and House, respectively, that would remove the ERA’s ratification deadline.  Known as the “three-state strategy,” this would allow the ERA to become part of the Constitution once three more states ratify it, joining the 35 who did so in the 1970s.

Which states ratified the ERA in the 1970s?

So many states ratified the ERA. Are there any state versions of the ERA?

There are 23 states that provide inclusive or partial guarantees of equal rights on the basis of sex. They include Alaska, California, Colorado, Connecticut, Florida, Hawaii, Illinois, Iowa, Louisiana, Maryland, Massachusetts, Montana, New Hampshire, New Jersey, New Mexico, Oregon, Pennsylvania, Rhode Island, Texas, Utah, Virginia, Washington and Wyoming.

What is different about this push to pass the ERA?

There’s been a rebirth of support around gender equality causes and feminism. Thestill widening wage gap is a constant topic of conversation in Hollywood and beyond. This year, the Supreme Court is going to hear its first major abortion case since 2007.

Coincidentally, the last major push to pass the ERA was also in 2007. Since then social media and other technologies have revolutionized not only the way we can talk to each other but also how we can communicate with our government.