Graffiti artists have been around ever since there were walls and things to draw or paint with—so, forever really. Murals are a more refined and planned out version of graffiti art and have historically been a much more accepted form of street art. Diego Rivera’s amazing murals, often depicting communist narratives, can be seen in Mexico City and even he was censored at times. In 1933, he began a piece in Rockefeller Center that was painted over after he refused to remove an image of Lenin. The depression was actually a boon for artists when Roosevelt created the WPA and commissioned numerous public art project in public building across the U.S.