Lamenting "a K-12 education system that is leaving vast numbers of students behind," Princeton President Shirley M. Tilghman encouraged the 2,021 graduates to help close the educational achievement gap. Here she addresses the crowd of 7,500 guests assembled on the front lawn of Nassau Hall for the University's 264th Commencement.

Photo: Princeton University, Office of Communications, John Jameson (2011)

Princeton senior John Pardon delivers the valedictory address at the University's Commencement ceremony, telling his peers that the completion of their undergraduate studies should not mark the end of their quest for knowledge.

Photo: Princeton University, Office of Communications, Denise Applewhite (2011)

Princeton senior Veronica Shi, a classics major from West Covina, Calif., delivers a salutatory poem in Latin at Princeton's Commencement ceremony. The Latin Salutatory, the University's oldest student honor, today often contains humorous tributes and a farewell to Princeton campus life.

Photo: Princeton University, Office of Communications, John Jameson (2011)

Heerang Kang gets help adjusting his robe from Amber Oliva before they begin the procession for Commencement.

Photo: Princeton University, Office of Communications, John Jameson (2011)

A group of classmates share a moment of togetherness before the Commencement procession begins.

Photo: Princeton University, Office of Communications, John Jameson (2011)

Parents and families are jubilant while holding signs and cheering for their graduates as the students pass by during the procession on the way to the Commencement ceremony.

Photo: Princeton University, Office of Communications, John Jameson (2011)

Princeton's front campus is a sea of mortarboards and gowns during the University's 264th Commencement ceremony, at which 2,021 undergraduate and graduate students were awarded degrees.

Photo: Princeton University, Office of Communications, John Jameson (2011)

Degree candidates from Princeton University's Graduate School pause to memorialize the moment during the Commencement ceremony.

Photo: Princeton University, Office of Communications, Denise (2011)

Provost Christopher Eisgruber recognizes the outstanding New Jersey secondary school teachers during the ceremony (from left): Robert Downes, Mountain Lakes High School, Mountain Lakes; Donata Nicholas, East Orange Campus High School, East Orange; Kathleen Chesmel, New Egypt High School, New Egypt; and Rachel Grygiel, Hoboken High School, Hoboken.

Photo: Princeton University, Office of Communications, Denise Applewhite (2011)

Faculty members recognized with President's Awards for Distinguished Teaching by President Shirley M. Tilghman (center) were (from left): Daniel Oppenheimer, Alexander Nehamas, Hendrik Hartog and Anne Case.

Photo: Princeton University, Office of Communications, Denise Applewhite (2011)

Honorary degree recipients pictured with President Shirley M. Tilghman (fourth from left) were: (from left): Judith Jamison, Susan Desmond-Hellmann, Robert Rawson Jr., Geoffrey Canada, Charles Gillispie and Henry "Hank" Aaron.

Photo: Princeton University, Office of Communications, Denise Applewhite (2011)

Baseball legend Henry "Hank" Aaron (center) receives his academic hood from chief marshal Douglas Clark after his introduction as an honorary degree recipient at Princeton's Commencement ceremony. Looking on (from left) are faculty marshal Angela Creager, Princeton President Shirley M. Tilghman, and columnist and University Trustee George Will.

Photo: Princeton University, Office of Communications, Denise Applewhite (2011)

Baseball Hall-of-Famer Henry "Hank" Aaron, who currently is senior vice president of the Atlanta Braves, waves to the crowd after receiving an honorary doctor of humanities for his "imperishable example of grace under pressure."

Photo: Princeton University, Office of Communications, Denise Applewhite (2011)

Princeton President Shirley M. Tilghman (left) joins the crowd in applauding honorary degree recipient Judith Jamison, a famed dancer and choreographer who is the artistic director of the Alvin Ailey American Dance Theater.

Photo: Princeton University, Office of Communications, John Jameson (2011)

Honorary degree recipient Geoffrey Canada (right), chief executive officer of Harlem Children's Zone, is congratulated by Princeton President Shirley M. Tilghman during the Commencement ceremony. Canada was honored for being "committed to helping disadvantaged children forge pathways out of poverty."

Photo: Princeton University, Office of Communications, Denise Applewhite (2011)

Princeton alumnus Robert Rawson Jr., who served from 1985 to 2005 on the University's Board of Trustees, including 13 years as chair of its executive committee, was awarded an honorary doctor of laws, recognizing his "devoted service to his alma mater."

Photo: Princeton University, Office of Communications, Denise Applewhite (2011)

Honorary degree recipient Susan Desmond-Hellmann (right), clinical researcher and chancellor of the University of California-San Francisco, receives her degree from associate chief marshal Angela Creager during the ceremonies. Desmond-Hellmann was honored for her "stellar career" as an oncologist, clinical scientist and businesswoman.

Photo: Princeton University, Office of Communications, John Jameson (2011)

Charles Gillispie, Princeton's Dayton Stockton Professor of History Emeritus, receives one of six honorary degrees awarded at the University's Commencement ceremony May 31, 2011. Gillispie, a founding figure in the field of the history of science, was conferred a doctor of humane letters.

Photo: Princeton University, Office of Communications, Denise Applewhite (2011)

Princeton students celebrate after officially being designated as graduates by tossing their mortarboards into the air.

Photo: Princeton University, Office of Communications, Denise Applewhite (2011)

Princeton's Commencement has been held on the front lawn of historic Nassau Hall since 1922. Mace bearer Jeff Nunokawa, professor of English, guides part of the academic procession in a ceremony steeped in tradition.

Photo: Princeton University, Office of Communications, John Jameson (2011)

Graduating students happily exit FitzRandolph Gate following Princeton's Commencement ceremony.

Photo: Princeton University, Office of Communications, John Jameson (2011)

New Princeton graduates jump for joy as they pass through FitzRandolph Gate, which leads from Princeton's front campus, where Commencement in held, to Nassau Street in Princeton Borough.

Photo: Princeton University, Office of Communications, John Jameson (2011)

Graduating students happily exit FitzRandolph Gate following Princeton's Commencement ceremony.

Photo: Princeton University, Office of Communications, John Jameson (2011)

Getting into the spirit of Princeton's school colors, Daisy Pfander (from left) gave her son, Travis Pfander, orange flowers for graduation. Catie Bartlett of the class of 2012 joined the celebration.

Photo: Princeton University, Office of Communications, Denise Applewhite (2011)

Irfan Kherani (middle) proudly displays his diploma after collecting it from the Wilson College residential college diploma distribution after Commencement. His father, Nizar Kherani, and mother, Nasim Kherani, came from Edmonton, Alberta, for the ceremony.

Photo: Princeton University, Office of Communications, John Jameson (2011)