The Unreported
Quoting from a recent article by Rick Perlstein, Farrell (and others in the comments) accept a proposition that the lack of contemporaneous media accounts of spitting indicate that their later appearance in historical narrative is mythological, and politically interested mythology at that.
I think this is a dubious way to understand the relationship between memory, history and reportage, and that most historians would not accept the evidentiary rule being proposed.
National and global mass media at any time in the last century are porous to everyday life in many respects: many practices, incidents, identities, discrete moments of great interest to historians which appear tangibly in other kinds of documentary evidence or in oral testimony were not represented in mass media. Even under the most optimal, uncensored conditions, journalists are not panoptic, nor are they prophetic. What becomes interesting to us at a later date, what seems to exemplify particular eras, is sometimes wholly unanticipated and unnoticed in contemporary news coverage.
Or, alternatively, is seen as "unworthy" of coverage in a particular time and place. We know full well now that many reporters knew about John F. Kennedy's sexual escapades, but none thought it appropriate to report. You could not say, reading the papers of that time, that Kennedy was sexually promiscuous; it would appear, by contrast, that Bill Clinton was vastly more promiscuous, if you just went by what appeared in the media. The difference is not in the phenomena but in the nature of what constituted news in each era. To some extent, in the context of antiwar spitting, some of those commenting on the CT entry and Perlstein's essay are forgetting the relative conservatism of American newspapers even late in the history of the Vietnam War on questions of antiwar activism.
More importantly, what is remembered, even if mythologized, sometimes has a deeper basis. When I studied "urban legends" concerned with commodities, for example, I was interested to read an essay by folklorist Gary Alan Fine that tackled the common presumption in the literature on urban legends and rumors that these were entirely invented (if interesting and telling) narrative. Fine observed that in some cases, it was possible to find literal evidence that something rather like the common form of the legend had actually happened somewhere once or twice, if not commonly so. (Say, for example, fast food that turned out to be something other than what it was advertised, the old "deep fried rat" story.)
The discussion also reminds me of an ancient methodological dispute in the writing of African history, now largely routinized and resolved. Once upon a time, you had structuralist anthropologists who argued that formal oral traditions in African societies had little formal historical content, and were largely reflective of either political and social issues in contemporary societies, or were moral and instructive stories about deeply universal human problems (kinship, for example). Then came historians who argued that formal oral traditions had quite literal historical content, and beyond that, historians and anthropologists who learned to treat stories, reported speech, conversation and rumor as historical evidence whose value couldn't be reduced or subtracted to simple literal stories about "what actually happened". The assumption that comes out of such work is that most of what people commonly talk about and believe to be true has some grounding in their actual experience of historical change, but also in ongoing contests over meaning, representation and knowledge which service existing social interests and factions.
That's all somewhat vaporous. The point in this case is whether or not the stories of spitting were reported in the newspaper may be a poor guide to whether or not they happened. Many people would now accept that an artist tried to throw Robert McNamara off a ferry at Martha's Vineyard (the story becomes credible as historical knowledge after reading or hearing about Paul Hendrickson's book on McNamara), but the incident wasn't reported at the time. Many events transpire outside of the eyes of the media, go unremarked upon in the public sphere, but travel through and within the knowledge of everyday life. As they travel, they become elaborated, disconnected from their original moment in historical time, acquire mythological and partisan encrustations, become a part of common sense. The distance travelled is sometimes from a morally ambiguous, complex, socially idiosyncratic truth about small incidents to a simplified and misused fiction, which is really what Perlstein is getting at. But the methodological standard proposed that would allow us to split the difference cleanly isn't a terribly useful one: historical knowledge does not permit such convenient disentanglements.