Gabrielle Giffords, 41, resigned from the U.S. House of Representatives Wednesday in an emotional ceremony on the House floor a little more than one year after she was shot in the head at an event for her constituents in Tucson, Arizona. Republican and Democratic lawmakers joined to give the Democrat repeated standing ovations and tearful embraces, and unanimously passed a border security bill she co-sponsored.

House Majority Leader Eric Cantor, a Republican from Virginia, recalled the shooting rampage on January 8 last year, saying the country will never forget those who lost their lives.

"A little more than a year ago, Americans witnessed a heinous attack on Congresswoman Gabby Giffords, her staff and the citizens of Tucson," said Cantor. "This attack took 6 innocent lives including [congressional aide] Gabe Zimmerman, injured 13 and shook all of us in the congressional community, and in fact our nation, to its core."

The shooter, Jared Loughner, is undergoing court ordered treatment for schizophrenia in a federal prison in Arizona with the goal of making him fit to stand trial.

In the House chamber, which is often the scene of intense partisan debate, lawmakers stood crying, cheering and clapping as Representative Giffords slowly made her way to the podium, holding the arm of her close friend, Democratic Representative Debbie Wasserman-Schultz.

Wasserman-Schultz wept as she read Giffords's letter of resignation, where Giffords explained she is resigning to focus on her recovery.

"From my first steps and first words after being shot, to my current physical and speech therapy, I have given all of myself to being able to walk back onto the House floor this year to represent Arizona's 8th Congressional District. However, today, I know that now is not the time," said Wasserman-Schultz.

Giffords then handed her letter of resignation to Republican Speaker of the House John Boehner, who hugged her and cried.

Before the shooting, Giffords was widely admired in the House for reaching across the aisle to work with her Republican colleagues to find common sense solutions to problems.

"Congresswoman Giffords' message of bipartisan and civility is one that all in Washington and in the nation should honor and emulate," said House Minority Leader Nancy Pelosi. "As Gabby said in her video, which moved us all so much this weekend, 'We can do so much more by working together.'"

After the resignation ceremony, the House of Representatives, including Giffords, voted on her final piece of legislation, a bill that would impose tougher penalties on smugglers who use small, low-flying aircraft to avoid radar detection and bring drugs across the U.S. southern border with Mexico. The measure passed by a vote of 408 to 0.