In January 1969 a local activist, John “Caker” Casey, painted a sign on a gable wall stating: “You are now entering Free Derry”. When the British Home Secretary, Jim Callaghan, visited Derry in August 1969, the “Free Derry” wall was painted white and the “You are now entering Free Derry” sign was professionally re-painted in black lettering. The houses on Lecky Road and Fahan Street were subsequently demolished, but the wall was retained. It has been repainted at frequent intervals.
The square became known as Free Derry Corner by the inhabitants, while the media called it “the area”. The square is located on the edge of the Bogside and, together with the surrounding streets, was the scene of the Battle of the Bogside in 1969 and Bloody Sunday in 1972. The square was where the first street fighting broke out during the battle. After victory in the Battle of Bogside, the residents celebrated at Free Derry Corner. [Source]