Is there such a thing as a Q factor in history – do historical events have a Q score? In the argot of public relations and advertising, the Q score measures the familiarity or appeal of a celebrity. To Cleveland professional sports fans, for example, LeBron James's Q is higher than that of former Browns quarterback and party boy Johnny Manziel.

The Mississippi Flood of 1927 has, in cultural history, a pizzazz that other natural catastrophes lack. Ten years later, the Ohio Valley (and lower Mississippi) Flood of 1937 was just as horrendous in its effects (and maybe more so in its long-lasting impact). But that 1937 flood "is a catastrophe lost to historians," as one of them, David Welky, has written.

The novels and Randy Newman songs and popular and academic histories, rather, made the 1927 Flood a focus; and so it is paramount in the popular memory. How this came to be, and the manifestations of that popular memory – how, in other words, the "most publicly consuming environmental catastrophe of the twentieth century in the United States assumed public meaning," is the subject of Susan Scott Parrish's ambitious new book The Flood Year 1927: A Cultural History.

As she shows, the phenomenon of the Flood (including its treatment in the press at the time, and the reactions to it, popular and governmental) was inextricably tied to our country's great dividers – north and south, and black and white. The biggest divider of them all, the Civil War, had ended (at least the live ammunition part of it – the removal-of-monuments-from-public-places part of it is still ongoing), sixty-two years earlier.

There were several narrative motifs in the national press during the Flood, which lasted for months, and inundated thirty thousand square miles and seven states. Nature was deemed an aggressor against white southerners, who were deemed feminine (or emasculated) and dependent; the North was the noble, and paternalistic, rescuer. Not surprisingly, Parrish says, southerners found the noblesse oblige "including the role-playing – to be dim-witted and aggravating."

This storytelling (that is, storytelling presented as good, factual, news reporting) had a purpose that was all but subconscious. In this and similar catastrophes, Parrish says, "journalism achieves a kind of ritual function as it finds itself called to transform a biological occurrence into a cultural occasion to reaffirm the bonds and values of the suffering community." So the Flood was presented, over and over, as a "war" between the river and the southern people who were, this time, defended by the northern people. It was a mythology, in short, of "an event to remedy the older war fought between North and South."

As for the portrayal of black people in the south, they were Hambones, "entr'acte minstrel figures of comic relief," shuffling their childlike ways through the Biblical-like rains – so they appear in the drawings of the editorial cartoonists of the time. (The book reproduces a number of newspaper cartoons on the subject of the flood; each is worth, as the old adage says, a thousand words at least, and each reminds the reader of an art form that has, sadly, been lost.) The exception to these backhanded slurs was the black press at the time – the Baltimore Afro-American, the Chicago Defender, the NAACP's Crisis magazine, and others – which protested, often eloquently and mostly to no avail, of the treatment to which blacks were subjected. On the one hand, they were segregated in bare-bones relief camps; at the other, they were forced to work, in perilous conditions, at reinforcing levees, in what amounted to a new slavery.

As one self-satisfied white politician said at the time, "in the saving of human life, in great humanitarian undertakings, we know no color line"; and, as Parrish responds, "such statements were patently false."

All of this cultural history is well researched and well argued though, it must be said, Parrish can take short-cuts, too. At a couple of points in the book, she says that the concept of race itself is not a scientific fact but rather a late-seventeenth or eighteenth-century invention. Without much explanation, only citation to Michel Foucault and Eric Williams, this is not so much convincing or illuminating as distracting.

The second half of The Flood Year 1927 undergoes a bit of a switch, from an able presentation of cultural history to something like historo-literary criticism. First comes an extended riff on a Bessie Smith song, "Back-Water Blues," as well as other blues songs of the time, which, musically or artistically significant as they may be, are here made to support more scholarly exegesis than, probably, they can bear.

The novelists William Faulkner and Richard Wright, both of whom wrote flood-connected works, take up most of the rest of the book, along with Thomas Mann and a number of other lesser lights. This final part is intelligent and not uninteresting. Still, the two halves of the book – the cultural history based mostly on contemporary journalism and the second, on literary sources – almost, but not quite totally, cohere.

Parrish disclaims that she is writing a "blow-by-blow narrative of the event itself," and no wonder: that kind of narrative has been done more than once, most notably in John M. Barry's magnificent 1997 book Rising Tide: The Great Mississippi Flood of 1927 and How it Changed America. But Parrish's book is more than an adjunct to Barry's – it stands on its own as a story ( and a magnificent one at that), of how we come to remember our history and how it can be mythologized as it is being made.