Urban Prep Academy senior Keith Greer, along with his classmates, celebrates the news they will receive a free prom in Chicago because 100 percent of the graduating class was accepted into 4-year colleges or universities. (Tribune photo by Heather Charles / March 5, 2010)

The entire senior class at Chicago 's only public all-male, all-African-American high school has been accepted to four-year colleges. At last count, the 107 seniors had earned spots at 72 schools across the nation.

Mayor Richard Daley and Chicago Public Schools chief Ron Huberman surprised students at an all-school assembly at Urban Prep Academy for Young Men in Englewood this morning to congratulate them. It's the first graduating class at Urban Prep since it opened its doors in 2006.

Huberman applauded the seniors for making CPS shine.

"All of you in the senior class have shown that what matters is perseverance, what matters is focus, what matters is having a dream and following that dream," Huberman said.

The school enforces a strict uniform of black blazers, khaki pants and red ties -- with one exception. After a student receives the news he was accepted into college, he swaps his red tie for a red and gold one at an assembly.

The last 13 students received their college ties today, to thunderous applause.

Ask Rayvaughn Hines what college he was accepted to and he'll answer with a question.

"Do you want me to name them all?"

For the 18-year-old from Back of the Yards, college was merely a concept--never a goal--growing up. Even within the last three years, he questioned if school, let alone college, was for him. Now, the senior is headed to the prestigious Morehouse College in Atlanta , Ga. next fall.

Hines remembers the moment he put on his red and gold tie.

"I wanted to take my time because I was just so proud of myself," he said. "I wanted everyone to see me put it on."

The achievement might not merit a mayoral visit at one of the city's elite, selective enrollment high schools. But Urban Prep, a charter school that enrolls using a lottery in one of the city's more troubled neighborhoods, faced difficult odds. Only 4 percent of this year's senior class read at grade level as freshmen, according to Tim King, the school's CEO.

"I never had a doubt that we would achieve this goal," King said. "Every single person we hired knew from the day one that this is what we do: We get our kids into college."

College is omnipresent at the school. Before the students begin their freshman year, they take a field trip to Northwestern University . Every student is assigned a college counselor the day he steps foot in the school.

The school offers an extended day--170,000 more minutes over four years compared to its counterparts across the city--and more than double the number of English credits usually needed to graduate.

Even the school's voicemail has a student declaring "I am college bound" before it asks callers to dial an extension.

Normally, it takes senior Jerry Hinds two buses and 45 minutes to get home from school. On Dec. 11, the day University of Illinois at Champaign- Urbana was to post his admission decisions online at 5 p.m., he asked a friend to drive him home.

He went into his bedroom, told his well-wishing mother this was something he had to do alone, closed the door and logged in.

"Yes! Yes! Yes!" he remembers screaming. His mother, who didn't dare stray far, burst in and began crying.

That night he made more than 30 phone calls, at times shouting "I got in" on his cell phone and home phone at the same time.

"We're breaking barriers," he said. "And that feels great."