The short answer: humans invented graffiti. Since there have been walls, people have been writing on them. Archaeologists have found graffiti on the Sphinx.
However, graffiti as we know it today started in New York City in the 1970's. Taki183 is generally cited as the first famous tagger, having been written about in the New York Times ("Taki183 Spawns Pen Pals", 21 July 1971.) Over the next few years graffiti became a more stylish, colorful art form, and in its early days it was most often seen on NYC subway cars. The first graffiti artists to be featured in a gallery were Lee Quinones and his screw, the Fab 5 Freddy. Other major players in the graffiti art movement include Jean-Michel Basquiat, Zephr, Seen, Cope2, and Phetus.
EMINEM
Nintendo
china
To have fun!
Not you lol
Sony
francinstin
no one knows
Charles Babbage
The ancient Greeks
Jesus
Wilhelm Röntgen