First lady Michelle Obama speaks to students about committing to education on Nov. 12, 2013, at Bell Multicultural High School in Washington. (Carolyn Kaster/AP) (Carolyn Kaster/AP)

Michelle Obama faced an auditorium of low-income students at Bell Multicultural High School in the District on Tuesday and urged them to aggressively chase a college degree, saying it would lift their own lives and the fortunes of the nation.

Obama’s appearance kicked off her new campaign to prod and inspire high schoolers around the country to graduate and enroll in college, trade school or some type of higher education. “We’re going to talk about the power that you have to fulfill your potential and unlock opportunities that you can’t even begin to imagine for yourselves right now,” she said.

She noted that the United States has slipped from first in the world in college graduation rates to 12th. “That’s not acceptable,” said Obama, who joined Education Secretary Arne Duncan at the Columbia Heights school. Her message focused on personal responsibility and hard work, not the administration’s education policies.

In highly personal terms, Obama spoke about her own education and the path that took her from a working-class home on Chicago’s South Side to the Ivy League and the White House.

“At 6 a.m. every morning, I had to get on a city bus and ride for an hour, sometimes more, just to get to school,” she said, describing her commute to one of the city’s most selective high schools. “And I was willing to do that because I was willing to do whatever it took for me to go to college.”

While President Obama and policymakers are trying to tamp down college costs and expand access, it’s up to students to seize opportunities, she said.

“But here’s the thing — and I want you to listen to this — at the end of the day, no matter what the president does, no matter what your teachers and principals do or whatever is going on in your home or in your neighborhood, the person with the biggest impact on your education is you,” she said. “It’s that simple.”

When Obama decided to try to win admission to Princeton University, she faced plenty of obstacles. “I knew I couldn’t afford to go on a bunch of college visits,” she said. “I couldn’t hire a personal tutor. I couldn’t enroll in SAT prep classes. We didn’t have the money.”

The worst part, she said, was discouraging words from others.

“And then — get this — some of my teachers straight up told me that I was setting my sights too high,” she said. “They told me I was never going to get into a school like Princeton. I still hear that doubt ringing in my head.”

Although her older brother was a student at Princeton and getting in was one of the proudest moments of her life, she said the challenges continued there.

Arriving at Princeton was like “landing on another planet,” she said. “But through it all, I kept that college diploma as my North Star. And four years later, I reached that goal, and then I went on to build a life I never could have imagined for myself.”

“I’m here today because my story could be your story,” she told the sophomores at Bell, of whom 63 percent are Latino and 33 percent black. About 85 percent of the students qualify for free or reduced-price lunch, a rough indicator of poverty.

“Maybe you come from a tough neighborhood,” Obama said. “Maybe one of your parents lost a job and you had to struggle just to get here today. These experiences are not weaknesses. They can teach you all kinds of things you can never learn in a classroom.”

For Sthefany Peña, 15, the first lady’s story was a revelation.

“You could start anywhere, like a rough neighborhood, and like she did, go to the top,” said Peña, a Bell student who lives in Northeast Washington and hopes to attend the U.S. Naval Academy.

The education effort expands the first lady’s focus on young people and gives her the opportunity to move beyond her well-honed niches of healthy eating and supporting military families. It marks a clear shift from the president’s first term, during which she rarely strayed from her two signature issues.

Obama’s interest in the area comes as the price of college education is rising faster at public colleges than private ones, raising questions about affordability. The administration has rolled out several Web sites to help students understand the cost of college at various institutions and the different kinds of grants and loans available.

The first lady’s new initiative plays to an appreciative crowd. Teenagers often make up her most responsive audiences.

She laid the groundwork for the new effort during the past several months at events with high school students, where she has encouraged them to pursue higher education as their primary job. She already had begun talking with young audiences about values she sees as essential for success, such as grit and determination.

Principal Maria Tukeva said Bell has been aggressively promoting college for the past few years, with freshmen able to take courses for college credit through the University of the District of Columbia and mandatory Advanced Placement English for all 11th- and 12th-graders. Last year, 82 percent of Bell’s graduating class enrolled in some type of post-secondary education, she said.

But when it comes to inspiration, a talk from the first lady beats a lecture from a guidance counselor, she said. “For them to hear it from her is great,” Tukeva said.