The House passed the FIRST STEP Act by a wide bipartisan vote today, sending the first major piece of criminal justice reform legislation in years to the White House for signing.

The FIRST STEP Act passed by a vote of 358-36 after sailing through the Senate Tuesday. Its passage is the culmination of a year of negotiations between Republicans and Democrats in Congress, law enforcement groups, the White House, and a coalition of conservative and liberal advocacy groups.

"The FIRST STEP Act is the most significant effort that the federal government will take to date to reduce federal prison populations after decades and decades of doing the opposite and trying to increase our prison populations," Inimai M. Chettiar, director of the Brennan Center's Justice Program, said in a conference call with reporters. "Of course, this bill is not going to end mass incarceration, but it is a significant and large step forward."

The legislation would expand reentry and job training opportunities for federal inmates and require them to be housed within 500 miles of their families, when possible. The version passed by the Senate also added four changes to federal sentencing law that would reduce some mandatory minimum sentences, expand judges' discretion under the so-called safety valve, and make the reductions to crack cocaine sentences under the Fair Sentencing Act of 2010 apply retroactively. The latter provision will result in reduced sentences for approximately 3,000 crack cocaine offenders in federal prison.

The FIRST STEP Act would also ban the shackling of pregnant female inmates in federal prisons. The Bureau of Prisons amended its policies in 2008 to bar the practice except in cases of flight risks, but there is no federal law against it. It's banned in all but six states now, but according to reports, the practice persists even where it's supposedly illegal.

"The idea that a woman needs to be shackled in labor and delivery as though she is going to escape while delivering a child is ridiculous, brutal, and a human rights abuse," Rep. Karen Bass (D-Calif.) said on the House floor prior to the vote.

Sitting in the House gallery above, watching debate over the bill, was Pamela Winn, a Georgia woman who suffered a miscarriage in federal prison after she fell while shackled by the ankles and wrists.

Reason interviewed Winn about her experience earlier this year:

"During the miscarriage, to hear people trying to figure out if they should call 911 or call the Marshals, that's reinforcement to me that there should be some sort of protocols in place," Winn says. "At that point I was concerned if I was going to live, because I'm bleeding out and these people don't know even what to do with me." "Once I got to the hospital, I'm shackled to the bed in excruciating pain," Winn continues. "I've got two male officers down between my legs that I don't know anything about. You're already experiencing a loss and then you have to be humiliated and embarrassed on top of that." "The lowest part for me was when the nurse stated that I had already passed the baby and she needed all of the linen that I had bled on prior to me getting to the hospital," Winn says. "[The officers] told her that they had thrown it in the trash. Just to hear that my baby was thrown in the trash, and the tone of the officers—like that was what they really felt about it, that it was trash—it's really hard. It's hard to come back from something like that. It was trash to them, but it was my child. It was a life. It was a part of me. My crime was about some money, and I'm sitting up there thinking to myself, there's no amount of money or nothing that I could have taken or did wrong to justify throwing my baby in the trash and treating me like I am trash."

Like many formerly incarcerated women, Winn is now an advocate for reforming the justice system. In a conference call with reporters shortly before the House vote, Winn said it was "humbling and monumental" to hear a member of Congress cite her story.

"It lets me know that my voice—the voice of all the incarcerated pregnant women that have come before me and are still there— it lets me know that we are being heard," Winn said. "It's an exciting and very dreamlike feeling to be able to contact my people I left on the inside and let them know that they're going to finally get relief after all this time."

Grassroots advocates like Winn spent the summer and fall traveling to D.C. to hold rallies and meet with members of Congress to share their stories.

In the White House, senior adviser and Trump son-in-law Jared Kushner worked to sway the president to support the bill.

In his State of the Union speech in January, Trump announced his administration would "embark on reforming our prisons to help former inmates who have served their time get a second chance." However, it was unclear if the notoriously flighty president would endorse a bill, especially over the objections of the Justice Department.

The FIRST STEP Act first passed the House in May. The sentencing reform measures were added to the legislation in the Senate, where a bipartisan group of senators including Senate Judiciary Committee Chairman Chuck Grassley (R–Iowa) had been working for several years to advance a criminal justice reform bill.

Trump endorsed the bill after the midterm elections in November, giving Republicans cover to support it and putting pressure on Senate majority leader Mitch McConnell to bring it to the Senate floor.

The compromise bill was supported by a wide coalition of conservative, evangelical, liberal, and criminal justice groups, but it was criticized from the "tough on crime" right—a "jailbreak" said Sen. Tom Cotton (R–Ark.)—and from the left, where activists saw it as a minor facelift to a ghoulish system.

The Appeal wrote today that the act is, at best, a baby step, and there are concerns about its heavy reliance on risk-assessment tools that critics say can reinforce bias in the justice system.

Progressives lawmakers and advocacy orgs were initially skeptical of the bill but the addition of several sentencing reforms in the Senate convinced many to ultimately support it.

"This bill was declared dead I think at least a dozen times," Jessica Jackson Sloan, co-founder of the criminal justice advocacy group #cut50, said. "So it all looks downhill right now, but this has been a fight for several years."

Sloan said she is "very hopeful that this is just the beginning of a renaissance period for criminal justice reform in this country," a sentiment echoed by both conservative and liberal groups.

"We look forward to President Trump signing this bill into law, and we must now continue moving the needle on justice reform even further towards fairness," Jason Pye, vice president of legislative affairs for FreedomWorks, a grassroots conservative advocacy group, said in a statement. "There is much work yet to be done, and Congress has overwhelmingly given its approval to continue down this path."