"I never thought I'd see the day," Air Force Intelligence Officer Ginger Wallace told the Washington Blade earlier this month. Colonel Wallace entered the military in 1990, and for the vast majority of her career, she knew that because of "Don't Ask, Don't Tell," she could be fired at any time, just for being a lesbian.

But times have changed. As Colonel Wallace prepares to deploy to Afghanistan in the spring, she can serve the country she loves, without hiding who she loves. In fact, when she was recently promoted, she invited her partner Kathy to pin her new rank to her jacket in a ceremony at the Pentagon -- without risking her career, or facing an investigation.

It's been exactly one year since President Obama signed the law repealing "Don't Ask, Don't Tell," and when we hear stories like Colonel Wallace's, we are reminded that when we work together, we have the power to change our country for the better. When it came time to end discrimination against gays and lesbians in the military, President Obama showed true leadership, the Pentagon completed a thorough and transparent planning process, a broad coalition of advocates made their voices heard, and Congress acted. Because they did, lesbian and gay service members will no longer be required to live a lie in order to help protect our country.

In his remarks at the signing ceremony one year ago, President Obama spoke about one of his visits to Afghanistan. "A young woman in uniform was shaking my hand," he said, "and other people were grabbing and taking pictures. And she pulled me into a hug and she whispered in my ear, 'Get 'Don't Ask, Don't Tell' done.' And I said to her, 'I promise you I will.'" To me, that story encapsulates President Obama's compassion, conviction, and determination.

Over the past year, the Pentagon implemented the new law, yet again demonstrating the professionalism and class that we have come to expect from the world's finest fighting force. Because they did so, "Don't Ask, Don't Tell" was completely repealed in September, and we are hearing more and more inspiring stories. For example, there's Captain Matthew Phelps, who blogged about bringing his date Brandon to this year's Marine Corps Birthday Ball. And on the White House web site, we've compiled many more stories about what this day means.

As President Obama has said, "Change has never been quick. Change has never been simple, or without controversy." But when we see pictures of Colonel Wallace and Kathy, or Captain Smith and Brandon, we know what change looks like.

Of course, ending DADT is only one part of an ongoing commitment to keep our nation safe and staying true to our values. This month, President Obama brought the war in Iraq to a close. As our troops come home, we are determined to serve all our veterans as well as they've served our great country.

And today, we're reminded that when we work together to make our union more perfect, change is not just possible, but inevitable. On this historic anniversary, we look forward to continuing to work with all those who love our country, and seek a more perfect union.