LAWRENCE — When Nathalie Marte and Genesis Giraldo graduate Central Catholic, they will close one chapter in their lives and immediately open another by attending college with $25,000 scholarships for each of the next four years.

Marte, 17, and Giraldo, 18, both of Lawrence, each received $100,000 scholarships from the Posse Foundation of Boston to help with college tuition.

The students were nominated by Adelante Inc., an after-school program where they are volunteers. To be eligible for the scholarships, they had to attend meetings and spent weekends at Posse partner schools.

"When I finally got it, it was one of the biggest blessings I've ever had," Giraldo said. "I cried tears of joys because my mom didn't have to worry about paying for college."

Posse Foundation identifies, recruits and trains student leaders from public or private high schools to form multicultural teams called "posses."

Each team is prepared during an eight-month pre-collegiate training program, for enrollment at universities nationwide where students pursue their academics and promote cross-cultural communication on campus.

Marte and Giraldo will be among 312 seniors graduating Central Catholic High School on May 23.

"It's surreal," said Marte, daughter of Marisol and Jose Marte. "My parents and I always talked about me getting a college education and to get the whole package deal is an added bonus. When you're part of the working class, getting a good education is your ticket out. The scholarship will make my dream come true."

Marte will study political science at Union College in Schenectady, N.Y., where tuition and books total $50,060 for the 2008-2009 school year.

Giraldo is just as ecstatic as she heads to Denison University in Granville, Ohio, to study international affairs and communication. Tuition and books at the school cost $45,980 for the 2008-2009 academic year.

"I couldn't see myself without going to college," said Giraldo, the daughter of Ramona Cruz and Samuel Giraldo. "I'll appreciate it more because she has worked so hard so I can go to Catholic school."

Marte was nominated by Central Catholic and Giraldo by Adelante, which also helped pay their way to Central Catholic.

"It's quite an amazing scholarship," said David Hildt, executive director of Adelante. "It's a remarkable program because it gives kids an opportunity to go to college who might otherwise not have a chance at high quality education."

Giraldo has been a member of Adelante since seventh grade.

"We're tremendously proud and happy for them," Hildt said. "We know that there are many more with the potential to be awarded scholarships in Adelante and around the city."

Marte joined the program in the eighth grade and tutored fourth- and fifth-graders and took part in the Upward Bound program. The young women also were active at Central Catholic. Marte was a member of the Model United Nations for three years. Giraldo has been involved in campus ministry, peer leadership and was a student ambassador.

"How prestigious is $100,000?" Hildt asked. "I've never met anybody in my life who has won as much as they have."

This is not the first time area residents have received the awards. Last year, Jatnna Amador, 17, and Christine Nguyen, 18, both of Lawrence and Shavely Peralta, 17, of Methuen won Posse scholarships.