I found today an excellent graffiti essay that was put online by Roy Christopher.
Some paragraphs of the article:
One of the major things that differentiates the human species from all other species on Earth is our ability to externalize subjective memory. To write things down. To store and exchange ideas outside of our brains. This all started with cave paintings and etchings. Graffiti, if you will, was the beginning of written history.
Graffiti proper, in the modern sense of the term, started in the late 1960s in New York City when a kid from the Washington Heights section of Manhattan known as Taki 183 („Taki” being his tag name and „183? being the street he lived on) emblazoned his tag all over NYC. He worked as a messenger and traveled all five boroughs via the subways. As such, he was the first „All-City” tagger. Impressed by his ubiquity and subsequent notoriety, many kids followed suit and graffiti eventually became a widespread renegade art form. Graff writers embellished their names with colors, arrows, 3-D effects and mad lettering styles.
You can read more on Roy Christopher’s site.