Im Januar 1895 war der Geschäitsführer des Verlags „Buchhandlung Vorwärts”, Richard Fischer, „beim Durchblättern alter Zeitungen” auf Marxens Artikel „Die Juniniederlage 1848”, „Der 13. Juni 1849” und „Folgen des 13. Juni 1849” gestoβen, welche 1850 in den ersten drei Heften der Neuen Rheinischen Zeitung. Politisch-ökonomische Revue erschienen waren. Am 30. des Monats bat er Engels in einem Brief um dessen Zustimmung zur Herausgabe der völlig unbekannten Marxschen Arbeit in Form einer Broschüre. Gleichzeitig ersuchte er ihn, eine Einleitung dazu zu verfassen. Da Fischer die Schrift spätestens im März herausbringen wollte – er hielt Engels vor Augen, daβ nach einer möglichen Annahme der Umsturzvorlage das Erscheinen der Marxschen Arbeit in Frage gestellt sei –, drängte er auf eine umgehende definitive Antwort. Engels monierte zwar am 2. Februar die Art und Weise, in der er zeitlich unter Druck gesetzt würde, stimmte aber dem Plan Fischers zu und versprach, die gewünschte Einleitung in Angriff zu nehmen. Darüber hinaus erweiterte er die Marxschen Artikel um jene Abschnitte aus der „Revue” des fünften und sechsten Heftes der Neuen Rheinischen Zeitung, die die Ereignisse in Frankreich behandelten. Aus drei Vorschlägen, die Engels machte, wählte Fischer den Titel „Die Klassenkämpfe in Frankreich 1848 bis 1850”.

Any historian who deals with a period in which conspirators played a significant role sooner or later comes up against the conspirator's twin brother, the undercover police agent. In most cases, the policeman revolutionary or revolutionary policeman, however fascinating as an entrée into the twilight world of double and triple agents, offers more to the enterprising journalist than to the historian. Even some of the more spectacular exemplars of real or reputed undercover agents – Roman Malinovsky, who rose to membership in the central committee of the Bolshevik party before 1917; Lucien Delahodde, who until his exposure was a leading light in the secret societies of the July Monarchy; Auguste Blanqui, the unquenchable revolutionary who may or may not have informed on his comrades in 1839 – did not really affect the general course of history, at least not as informers. Though Malinovsky as a psychological phenomenon cries out for a latter-day Dostoevsky, his amazing career did not in any way deflect the Bolsheviks from their goal. Delahodde's more businesslike relations with the Orleanist police sapped an underground republican movement which was already impotent and discredited before he joined it. In Blanqui's case, the question of guilt or innocence is almost irrelevant, though the accusation of treason which the journalist Taschereau levelled in March 1848 did foil Blanqui's efforts to lead the left-wing opposition to the Provisional Government.

Social historians studying nineteenth-century England tend to concentrate on the work-situation, and therefore on the conflicting interests of employer and employee. Dr John Vincent, however, has recently directed attention to the popular basis of nineteenth-century Liberalism; this brings into the forefront quite different social alignments – especially when conflicts over religion and recreation are investigated. Popular radicalism “was the product of the leisure of Saturday night and Sunday morning, the pothouse and the chapel, not of the working week”. This shift in interest brings the drink question to the fore, as several scholars have already realised: “it would be hard to say why historians have not rated the effect of strong drink as the significant factor in nineteenth-century history that it undoubtedly was”, wrote Dr Kitson Clark recently; “its importance stands out from every page of the contemporary record”. W. L. Burn thought it “arguable” that the Beer Act of 1830 was “more revolutionary in its immediate social consequences than any other of the reforming age”.

At the very beginning of the investigation, it is necessary to find a word to describe the European masses before the coming of the twin revolutions, the French and Industrial, that have contributed so much to the making of the modern world. “Proletariat” is clearly anachronistic; “wage-earners” is inadequate in a society where cash wages were far from being the most common form of payment for labor. “Working class” is too much identified with nineteenth century developments and, what is worse, conjures up an image of a homogeneous group that does not conform to eighteenth century realities. “Laboring poor” is by far the best, for it emphasizes two primary facts about the people with whom we are concerned: first, that, to one extent or another, they earned their living by doing manual labor, and, second, that they were being continuously impoverished, as Professor Labrousse has shown. The category has several virtues as a tool of historical analysis. It is large enough to take account of the complexities of eighteenth century social conditions, stressing the mobility and social intercourse that existed, albeit on a diminishing scale, between the master artisans and shopkeepers, their apprentices and journeymen on the one hand, and the domestics, beggars, criminals and floating elements in the population, on the other. Classes laborieuses and classes dangereuses lived side by side and recruited their personnel from one another. They did in fact form a whole, whom contemporaries called “les classes inférieures”. If we look toward the future, we see that the French Revolution Was to bring about a temporary split in their ranks by politicizing those among them who became the sans-culottes, and that the Industrial Revolution was to complete this division on other bases by allowing some of the laboring poor to become petty capitalists, While forcing the majority to become proletarians or to fall further still into the nether world of the lumpen-proletariat. In sum, the use of the concept of the laboring poor enables us to come close to the reality of eighteenth century paris and to watch the disagregation of that reality with the passage of time.