The lifetime accomplishments of 16 activists, entertainers, doctors, scientists and athletes will be awarded the highest civilian honor this afternoon, known as the Presidential Medal of Freedom. The awards, presented by President Barack Obama recognizes individuals “who make an especially meritorious contribution to the security or national interests of the United States, world peace, cultural or other significant public or private endeavors.”

This year’s awardees include a diverse group of African American, Latino, Native American, white and South Asian notable figures who were chosen for their work as “agents of change.” Many of the recipients have diverse backgrounds and achievements in fields ranging from sports and art to science and medicine to politics and public policy.

The Medal of Freedom award was first established in 1945 by President Harry S. Truman to recognize civilians for their efforts during World War II. It was reinstated in 1963 by President John F. Kennedy to honor distinguished service.

Here are some of the recipients:

Sen. Edward M. Kennedy, D-Mass., who has been battling brain cancer, has served in the U.S. Senate for 46 years. He is known by many as one of the greatest lawmakers and leaders of our time. From reforming public schools to strengthening civil rights laws and supporting working Americans, Kennedy has dedicated his career to fighting for equal opportunity, fairness and justice for all. One of his biggest accomplishments is his steadfast and tireless effort to ensure that every American has access to quality and affordable health care. And he has been successful in doing so for countless children, seniors, and Americans with disabilities. Kennedy calls health care reform the “cause of his life,” and has championed nearly every health care bill enacted in Congress over the course of the last five decades.

Rev. Joseph Lowery has been a civil rights leader since the early 1950s. Lowery headed the Alabama Civic Affairs Association in, the organization that led the movement to desegregate buses and public accommodations in Mobile. Lowery later co-founded the Southern Christian Leadership Conference alongside Dr. Martin Luther King Jr. He was chosen by Dr. King to chair the delegation delivering the demands of the Selma-to- Montgomery march to Alabama Governor George Wallace. Lowery is a minister in the United Methodist Church and continues to highlight important civil rights issues in the U.S. and worldwide, including speaking out against apartheid in South Africa.

Sidney Poitier is a groundbreaking actor who became the top black movie star in the 1950s and 1960s. He was the first African American to be nominated and win a Best Actor Academy Award, as well as receive an award at a top international film festival (Venice Film Festival), and the first top grossing movie star in the U.S.

Billie Jean King was an acclaimed professional tennis player in the 1960s and 1970s, and helped champion gender equality issues not only in sports but in all areas of public life as well. King beat Bobby Riggs in the “Battle of the Sexes” tennis match, which was the most viewed match in history. She became one of the first openly lesbian major sports figures in the U.S. when she came out in 1981.

Sandra Day O’Connor was the first woman ever to sit on the United States Supreme Court, nominated by President Reagan in 1981 and served until her retirement in 2006.

Harvey Milk became the first openly gay elected official from a major city in the U.S. when he was elected to the San Francisco Board of Supervisors in 1977. Milk encouraged lesbian, gay, bisexual, and transgender citizens to live their lives openly and believed coming out was the only way they could change society and achieve social equality. He was shot and killed while in office in 1978. Milk is revered nationally and globally as a pioneer of the LGBT civil rights movement for his exceptional leadership and dedication to equal rights.

The other recipients include:

Anglican Archbishop Desmond Tutu of South Africa.

Nancy Brinker, founder of Susan G. Komen for the Cure, a leading breast cancer grass-roots organization.

Dr. Pedro Jose Greer Jr., assistant dean of academic affairs at Florida International University School of Medicine.

Stephen Hawking, Cambridge University physicist and mathematician known for his work on black holes who has been almost completely paralyzed for years and communicates through an electronic voice synthesizer.

Joe Medicine Crow, the last living Plains Indian war chief, who fought in World War II wearing war paint beneath his uniform.

Chita Rivera, actor, singer, dancer and winner of two Tony Awards.

Mary Robinson, Ireland’s first female president and one-time U.N. high commissioner for human rights.

Dr. Janet Davidson Rowley, professor of medicine at the University of Chicago.

Muhammad Yunus, the 2006 Nobel Peace Prize laureate for his global, pioneering work extending “micro loans” to poor people who don’t have collateral.

Jack Kemp, former Republican congressman of New York who was a quarterback-turned-politician who died last May.