
Sales' request for summary judgment, and Keep On Truckin' became public domain. The drawing had also appeared on the business card of Crumb's publisher without the copyright symbol. The work was protected by the terms of the 1909 Copyright Act, and any omission of notice was considered to cause the work to be public domain. Sales claimed the work was in the public domain, because Crumb had not included the copyright symbol on the work, although he had done so in Zap #1 as a whole. Federal Court, and was heard by Judge Albert Charles Wollenberg, who had previously ruled against use of Walt Disney's characters in cartoon parodies by the cartoonists for the Air Pirates cartoons. In 1973, Crumb's case was accepted by U.S.


Sales continued to sell unlicensed products after the settlement without paying additional fees. Sales, a producer of unlicensed Keep On Truckin' merchandise, reached a settlement of $750 for the past usage, but A.A. During the early 1970s, Crumb's lawyer started threatening lawsuits against anyone using the image without permission. The image has been imitated often without permission, appearing on T-shirts, posters, belt buckles, mudflaps, and other items. The cartoon's images were imitated and much displayed during the hippie era. A visual burlesque of the lyrics of the Blind Boy Fuller song "Truckin' My Blues Away", it consists of an assortment of men, drawn in Crumb's distinctive style, strutting across various landscapes. Keep On Truckin' is a one-page cartoon by Robert Crumb, published in the first issue of Zap Comix in 1968.

Original 1968 Keep On Truckin' cartoon, as published in Zap Comix.
