It is a moment that will live on in sports history—Brandi Chastain sliding to her knees, whipping her shirt above her head in jubilation after winning the 1999 World Cup for the United States against China with a penalty kick after 120 minutes of soccer. 

It was an important moment on so many levels. Important for women's sports. Important for soccer in the United States. Important simply because of how iconic the image of Chastain became. 

But that tournament in general represented a sea change in many ways, and showed to the world just how compelling the women's game was. FIFA.com did a wonderful job of putting that tournament in perspective:

The tournament was played in huge stadiums for the first time, and new heights were reached for attendance, media coverage and television audiences.

Spectator figures topped 660,000, the media numbered near 2,500. All 32 games were broadcast live on national television, and an estimated 40 million viewers in the U.S. alone watched the American hosts capture their second World Cup title, thrilling a nation and becoming the story of the year.

"This World Cup was a world-class, world-caliber, stand-alone event for women like none other," said Marla Messing, CEO of the U.S. organizing committee. "In a small way, we were all a part of history."

To this day, the final remains the most-watched soccer game ever in the United States. 

Now, that team will be remembered in The 99ers, a new documentary in ESPN's "Nine for IX" series celebrating women's sports. Here's the trailer:

Here's director Erin Leyden talking about the making of the film:

And here is ESPN's Robin Roberts talking about covering the famous event:

How cool is that?

The win for the United States did so much in this country to legitimize soccer, often a sport ignored by American fans in favor of domestic games such as baseball, football and basketball. And it was the women's national team—long a more successful side than the USMNT on the international stage—that brought more awareness to the game. 

And beyond that, it was a banner moment for female sports in general. With the entire world watching, the women put on an amazing show. 

Today, soccer has grown in popularity by leaps and bounds. Major soccer leagues around the world are televised in the United States. The MLS continues to grow. The National Women's Soccer League is alive and well. 

And the women keep on providing wonderful moments for American soccer fans. Who will ever forget Abby Wambach's legendary goal against Brazil in the 2011 World Cup?

It's important to remember just how relevant the 1999 World cup remains, and how it changed soccer and female sports in this country. You may always remember Chastain taking over her shirt and whipping it around in celebration, but that moment was the culmination of a wonderful tournament and a wonderful team.