Iconic singer, Aretha Franklin, the "Queen of Soul" passed away on Thursday after a battle with pancreatic cancer. She was 76.

Franklin was considered by many to be the greatest singer of all time. Her influence on popular music cannot be overstated. The legendary artist sold 75 million records and earned 18 Grammys in a career spanning six decades and she was influential in many global social movements as well.

Having been a widely-embraced public figure for so long, Franklin was present for some of the biggest events of the 20th century, including the funeral of Civil Rights Leader Martin Luther King Jr., as well as the release of Nelson Mandela from prison in 1990.

Upon Mandela's release, the singer played a unique role in welcoming him to the States by performing at a freedom rally in his honor in Detroit. Rosa Parks, Jesse Jackson and Stevie Wonder were also in attendance for the historic night. During the celebration, Franklin called the anti-apartheid leader on stage, where he spoke about listening to and appreciating "the Detroit, Motown Sound" while he was in prison.

Watch her unforgettable performance of "The Impossible Dream" below.

"His spirit and his ideals, and his heart and his soul could not be imprisoned," the late singer told ABC News after his death in 2013. When asked which song she would sing as a tribute to him following his death if she had to pick, Franklin responded "'Respect,' no question about it."

Her 1990 concert wasn't the only time she payed tribute to the South African leader. She performed a moving rendition of "Make Them Hear You" on Mandela Day in 2009 at New York's Radio City Music Hall. Watch her performance below.

In Febuary 2014, just two months after Mandela's death, the artist sang another tribute to him at BET Honors, this time delivering a heartfelt performance of Sam Cooke's classic "A Change is Gonna Come." You can watch her full performance from that night via BET.

There's no doubt that Franklin will be honored in the same way that she so graciously honored Mandela throughout his life. Fellow artists, fans, public figures and former presidents alike have taken to social media to share heartfelt tributes to the Queen of Soul. Barack and Michelle Obama have sharedparticularly heartfelt messages to the singer who performed at Obama's inauguration in 2009, read them below along with messages from Angelique Kidjo, Cynthia Erivo, Ibeyi and more.