When Eric Holder steps down as attorney general after nearly six years as the nation’s top lawyer, he will leave behind a legacy on LGBT-rights that is unmatched.

The nation’s first African-American attorney general and the fourth longest to hold the position, Holder’s record at the Justice Department is sprawling. It includes enforcement of major civil rights initiatives, including lawsuits against Texas and North Carolina for restrictive voting laws, as well as reforms to the criminal justice system. There are a fair share of controversies as well that have made him no favorite of Republicans on Capitol Hill. But it is Holder’s record on LGBT-rights that seems most likely to endure, not only for the impact it has had on LGBT Americans and the nation’s legal landscape, but also for its boldness.

“As younger men, Eric and I both studied law, and I chose him to serve as attorney general because he believes, as I do, that justice is not just an abstract theory. It’s a living and breathing principle,” Obama said Thursday as Holder announced his resignation. “Several years ago he recommended that our government stop defending the Defense of Marriage Act — a decision that was vindicated by the Supreme Court and opened the door to federal recognition of same-sex marriage and federal benefits for same-sex couples. It’s a pretty good track record.”

It was in February 2011 that Holder announced the Obama administration and the Justice Department would no longer defend the constitutionality of Section 3 of the Defense of Marriage Act (DOMA), which defined marriage as between a man and a woman for federal purposes.

“After careful consideration, including a review of my recommendation, the President has concluded that given a number of factors, including a documented history of discrimination, classifications based on sexual orientation should be subject to a more heightened standard of scrutiny,” Holder said in a statement at the time. “The President has also concluded that Section 3 of DOMA, as applied to legally married same-sex couples, fails to meet that standard and is therefore unconstitutional. Given that conclusion, the President has instructed the Department not to defend the statute in such cases. I fully concur with the President’s determination.”

According to Roberta Kaplan, the New York City attorney who represented Edith Windsor in her challenge of DOMA, which ultimately led the U.S. Supreme Court to strike down Section 3 of that legislation in June 2013, the announcement by Holder was the most surprising thing that happened in the case.

“We knew that this case would cause them to consider this. But when the president decided to do that, I had tears streaming down my face,” Kaplan told Metro Weekly in June. “And I really believe in my heart of hearts that it’s not a coincidence that it was three African-American guys — [President Barack Obama, Attorney General Eric Holder and Assistant Attorney General of the Civil Division Tony West] — who made that decision. I think they sat down and they said to themselves, ‘This is what we would have to say if we were going to write a brief saying that gay people shouldn’t get heightened scrutiny and we’re not willing to say this. As three African-American men, we will not put that down on paper.’”

When the Supreme Court did throw out the federal government’s definition of marriage as between a man and a woman, Obama was quick to act. On June 26, 2013, the same day the Windsor decision was issued, Obama instructed the Justice Department to work with members of his cabinet to ensure the decision was implemented swiftly and broadly across the federal government. Nearly one year later, Holder announced the decision had been implemented across the federal government “to the greatest extent possible under the law” in a memo to Obama.

Speaking to the at the winter meeting of the National Association of Attorneys General in February, Holder appeared to give state attorneys general the green light to stop defending bans on same-sex marriage. “I believe we must be suspicious of legal classifications based solely on sexual orientation,” Holder said at the time. “And we must endeavor – in all of our efforts – to uphold and advance the values that once led our forebears to declare unequivocally that all are created equal and entitled to equal opportunity.”

Under Holder, the Civil Rights Division has racked up the most hate crime convictions in more than a decade as the FBI and Civil Rights Division began actively investigating and prosecuting hate crimes based on sexual orientation and gender identity with the implementation of the Matthew Shepard and James Byrd, Jr. Hate Crimes Prevention Act.  

And during a Lambda Legal reception in June, Holder took aim at the Boy Scouts of America’s remaining ban on gay Scout leaders, comparing it to “Don’t Ask, Don’t Tell” and describing it as “a relic of an age of prejudice and insufficient understanding.” 

According to Chad Griffin, president of the Human Rights Campaign, Holder’s record is unmatched. “Some Attorneys General wait for history, others make history happen. Attorney General Holder made history for the LGBT community,” Griffin said in a statement. “He was our Robert F. Kennedy, lightening the burden of every American who faces legal discrimination and social oppression. We owe him a profound debt of gratitude for his legacy of advocacy and service.”

Griffin, who has encouraged Obama to nominate the nation’s first out LGBT cabinet member, says Holder’s resignation provides a “historic opportunity” for Obama to pick an attorney general who reflects the full diversity of the American people. “It would be a natural extension of this administration’s enduring commitment to equality to send a message of visibility and inclusion by nominating such a candidate to serve in this historic role,” Griffin said. NBC News reported Wednesday that Jenny Durkan, who is a lesbian and stepping down from her post as U.S. attorney for the Western District of Washington later this month, was described as possible replacement by a top Democratic Hill aide.

Announcing his resignation from the State Dining Room of the White House Thursday, Holder said that over the past six years the Obama administration has made “historic gains in realizing the principles of the founding documents,” among them advances for LGBT-rights.

“We have begun to realize the promise of equality for our LGBT brothers and sisters and their families,” Holder said.

But the book may not be closed just yet on Holder’s LGBT-rights record. Holder has agreed to stay on as attorney general until Obama names a successor who is confirmed by the Senate, which could take months. During an interview with ABC News in July, Holder indicated that when the issue of marriage equality once again comes before the nation’s highest court, the Obama administration will file a brief advocating for same-sex couples’ right to marry.

“I think we will file a brief that is consistent with the actions that we have taken over the past couple of years,” Holder told ABC’s Pierre Thomas. “We did not defend the Defense of Marriage Act. We were vindicated by the Supreme Court. The president then asked us to make the promise of the Windsor decision real. I sent a letter to the president just a couple weeks ago that talked about all the things we have done to knock down the barriers that still exist for same-sex married couples.”

According to Holder, these actions leave the Obama administration arguing that state bans on same-sex marriage are unconstitutional the logical next step.

On Monday, Sept. 29, the Supreme Court justices will meet behind closed doors to consider seven petitions asking the high court to hear cases challenging same-sex marriage bans in five states: Utah, Oklahoma, Virginia, Indiana and Wisconsin. Although the Supreme Court has no obligation to take any of the cases, nor are they restricted to a specific timeframe for announcing their decisions, should Holder still be head of the Justice Department when the high court hears such a case he has made clear they will make their views known to the justices.

“We’re proud of what we have done,” Holder said earlier this summer. “If a case comes before the Supreme Court we will file something consistent with what we have done that will be in support of same-sex marriage.”