Though former South Africa President Nelson Mandela remains in a Pretoria, SA hospital, the world is celebrating his 95th birthday.
The National Underground Railroad Freedom Center is marking the occasion by continuing its "Six Words for Mandela" campaign. Guests are invited to leave words of thanks and well wishes for the man known as "Madiba." The cards will eventually be sent to Mandela's family.
You can also send messages on social media using the hashtag #6Words4Mandela.
In 2010, Mandela was invited to visit the Freedom Center but was unable to travel because of his health. His daughter later visited in his stead. Mandela's close friend Archbishop Desmond Tutu was the 2000 recipient of the museum's annual International Freedom Conductor Award.