Joplin, Missouri (CNN) -- Calling the students an inspiration "to me (and) the world," President Barack Obama urged Joplin High School graduates Monday to heed the lessons they've learned and spirit they've shown to rebuild not only their tornado-ravaged Missouri city, but also their nation.
"America only succeeds when we all pitch in and pull together -- and I'm counting on you to be leaders in that effort," said Obama. "Because you are from Joplin. And you've already defied the odds."
Minutes after 450 seniors from the same Missouri school got their diplomas last May 22, a monster twister tore through the community. More than 161 people were killed -- the worst death toll for such a tornado since modern record-keeping began in 1950 -- while dozens of buildings were torn to shreds by winds as strong as 200 mph.
One of them was Joplin High School itself, with the damage so severe that students ended up attending classes in a vacant section of the city's Northpark Mall.
Monday night's graduation ceremony was personal, with students reflecting with humor and perspective on their tumultuous school days and one administrator leading them in a chant to show their "Eagle pride."
"No matter where you are or what you do, your Joplin family loves you and believes in you," said school district Superintendent C.J. Huff, fighting back tears. "We are so very proud of you."
Obama alluded to students' unique struggles during his own commencement address, which was held on the campus of Missouri Southern State University. He referred, too, to broader challenges facing they their townsfolk to work together, dream big and remain positive in adopting a new slogan of "Remember. Rejoice. And rebuild."
"We can define our own lives not by what happens to us, but by how we respond," said the president, who returned to Joplin for the first time since attending a memorial service a week after the disaster.
"We can choose to carry on, we can choose to make a difference in the world. And in doing so, we can make true what's written in scripture: that 'tribulation produces perseverance, and perseverance (produces) character, and character, hope.'"
The story of Joplin also showed there are "so many good people in this world," something that he insisted the students never forget.
While Joplin has worked fast to rebuild, many of the hundreds of businesses destroyed by the tornado have not been able to get back to full speed. Some 332 households still live in Federal Emergency Management Agency trailers and are unable to rebuild their homes.
But they've gotten some help. The White House released a statement Monday noting the federal government has approved $21 million for directly affected Missouri residents, not including $97 million to the state of Missouri to support rebuilding projects and $41.3 million in low-interest disaster loans via the U.S. Small Business Administration for individuals, businesses and non-profit groups.
And the city of Joplin -- which is calling Tuesday's anniversary a Day of Unity, with events including a commemorative walk through the city -- estimates that almost 130,000 volunteers have logged hundreds of thousands of hours since the tornado.
It was during his remarks about community and unity that Obama shifted from discussing Joplin more exclusively, to talking about the nation in general.
"We need God. We need each other. We are important to each other. And we're stronger together than we are on our own," he said. "That's the spirit that's allowing all of you to rebuild this city. It's the same spirit we need right now to help rebuild America."
The Joplin High graduates are particularly qualified to do so, according to Obama. They have walked the walk -- by pitching in to assist their neighbors, pursuing their education despite the chaos around them and learning from other city citizens and total strangers about what people can do, against the odds, when they work together.
"Some of life's strongest bonds are the ones we forge when everything around us seems broken," the president said. "And even though I expect some of you will ultimately end up leaving Joplin, I'm convinced that Joplin will never leave you."