It is quite absurd to claim that Marx did not know that word. Although, in his most important writings the exact letter sequence is indeed not recorded. For example: It is not in the German version of the first edition of the first volume of Das Kapital In lesser known works — it is present.
It was a prominent word used by economist David Ricardo which Marx studied extensively and also a prominent word to be found in German historian Theodor Mommsen's work, published prior to Marx Das Kapital.
What is true is that Marx clearly preferred to talk of "capitalists" and kapitalistische Produktionsweise:
Mit Hofmann hast Du ganz recht. Du wirst übrigens aus dem Schluß meines Kapitels III, wo die Verwandlung des Handwerksmeisters in Kapitalist – in Folge blos quantitativer Aenderungen – angedeutet wird, ersehn, daß ich dort im Text Hegels Entdeckung über das Gesetz des Umschlags der blos quantitativen Aenderung in qualitative citire als gleich bewährt in Geschichte u. Naturwissenschaft. Karl Marx: Das Kapital. Bd. 1. Buch 1. Hamburg 1867. S. 288 (MEGA² II/5. 246.42–44.).
— Karl Marx an Friedrich Engels in Manchester. London, Samstag, 22. Juni 1867 IISG, Marx-Engels-Nachlass, L 4479/L VI 612 in MEGA
Or in Das Kapital:
Diese Voraussetzung ist gleich Voraussetzung der Nichtexistenz der kapitalistischen Produktion und daher der Nichtexistenz des industriellen Kapitalisten selbst. Denn der Kapitalismus ist schon in der Grundlage aufgehoben durch die Voraussetzung, daß der Genuß als treibendes Motiv wirkt, nicht die Bereicherung selbst.
— MEW: 3. Kapitel. Der Kreislauf des Warenkapitals | Inhalt | 5. Kapitel. Die Umlaufszeit –– Seitenzahlen verweisen auf: Karl Marx - Friedrich Engels - Werke, Band 24, "Das Kapital", Bd. II, 1. Abschnitt, S. 104 - 123 Dietz Verlag, Berlin/DDR 1963 VIERTES KAPITEL Die drei Figuren des Kreislaufsprozesses
What is in part true is that "kapitalistische Produktionsweise" (capitalist mode of production) and "Kapitalismus" are not exactly the same, but in practice meaning as much, when Marx uses it, very frequently. Remember that Marx was himself not a Marxist.
The important sections from the 1867 edition of Das Kapital:
Der Reichthum der Gesellschaften, in welchen kapitalistische Produktionsweise herrscht, erscheint als eine „ungeheure Waarensammlung"*), die einzelne Waare als seine Elementarform, […]
Der Augenschein lehrt ferner, dass in unsrer kapitalistischen Gesellschaft…
— Karl Marx: Das Kapital", Erstes Buch. Der Produktionsprozess des Kapitals. Erstes Kapitel. Waare und Geld. p1&p2, Otto Meissner: Hamburg, 1867.
In the very sticklish approach one might argue that the quote above including the exact word "Kapitalismus" is from the second volume of Das Kapital, which was published in 1885, two years after Marx' death. (Volume 3 is regarded as Engels doing more than 'just compiling', Volume 2 is said to be from Marx's own words and manuscripts…) But it seems that the word already is in Marx' own manuscripts for the second volume:
Denn der Kapitalismus schon in der Grundlage aufgehoben durch die
Voraussetzung, dass der Genuss als treibendes Motiv wirkt, nicht die
Bereicherung selbst.
— Karl Marx, MEGA, II/11: "Das Kapital", 2. Band, Manuskripte 1868–81, p682
In the better known original writings of Marx himself the exact letter sequence Kapitalismus is indeed absent. But since he had read authors using that word, described the underlying system as 'capitalist modes of production' its proponents and beneficiaries as 'capitalists', and differentiated between capitalis production modes and capitalist societies, it is obvious that he just preferred a in his view more exact descriptor for what he wanted to express.
Now, in his letter to Wera Sassulitsch from 1881 we find this:
Mit einem Wort, sie findet den Kapitalismus in einer Krise, die erst mit seiner Abschaffung, mit der Rückkehr der modernen Gesellschaften zum "archaischen" Typus des Gemeineigentums enden wird, oder, wie ein amerikanischer Autor |L. H. Morgan|, der keineswegs revolutionärer Tendenzen verdächtig ist und in seinen Arbeiten durch die Regierung in Washington unterstützt wird, es sagt - das neue System, zu dem die moderne Gesellschaft tendiert, "wird eine Wiedergeburt (a revival) des archaischen Gesellschaftstypus in einer höheren Form (in a superior form) sein". Man darf sich nur nicht allzusehr von dem Wort "archaisch" erschrecken lassen.
In a word, it finds capitalism in a crisis that will only end with its abolition, with the return of modern societies to the "archaic" type of common property, or, as one American author put it |L. H. Morgan|, who is by no means suspicious of revolutionary tendencies and who is supported in his work by the government in Washington, it says - the new system, to which modern society tends, "will be a rebirth (a revival) of the archaic type of society in a higher form (in a superior form)". One must not be too frightened by the word "archaic".
— Seitenzahlen verweisen auf: Karl Marx/Friedrich Engels - Werke. (Karl) Dietz Verlag, Berlin. Band 19, 4. Auflage 1973, unveränderter Nachdruck der 1. Auflage 1962, Berlin/DDR. S. 384-406. Korrektur: 1 – Erstellt :18.07.1999 – Karl Marx –
[Entwürfe einer Antwort auf den Brief von V. I Sassulitsch] – Geschrieben Ende Februar/Anfang März 1881. – Nach der Handschrift. Aus dem Französischen.
Or here:
Welche Anwendung auf Rußland konnte nun mein Kritiker machen von dieser geschichtlichen Skizze? Einfach nur diese: Strebt Rußland dahin, eine kapitalistische Nation nach westeuropäischem Vorbild zu werden - und in den letzten Jahren hat es sich in dieser Richtung sehr viel Mühe kosten lassen -, so wird es dies nicht fertig bringen, ohne vorher einen guten Teil seiner Bauern in Proletarier verwandelt zu haben; und dann, einmal hineingerissen in den Wirbel der kapitalistischen Wirtschaft, wird es die unerbittlichen Gesetze dieses Systems zu ertragen haben, genauso wie die andern profanen Völker. Das ist alles. Aber das ist meinem Kritiker zu wenig. Er muß durchaus meine historische Skizze von der Entstehung des Kapitalismus in Westeuropa in eine geschichtsphilosophische Theorie des allgemeinen Entwicklungsganges verwandeln, der allen Völkern schicksalsmäßig vorgeschrieben ist, was immer die geschichtlichen Umstände sein mögen, in denen sie sich befinden, um schließlich zu jener ökonomischen Formation zu gelangen, die mit dem größten Aufschwung der Produktivkräfte der gesellschaftlichen Arbeit die allseitigste Entwicklung des Menschen sichert. Aber ich bitte ihn um Verzeihung. (Das heißt mir zugleich zu viel Ehre und zu viel Schimpf antun.)
What application to Russia could my critic make of this historical sketch? Just this one: If Russia aspires to become a capitalist nation on the Western European model - and in recent years it has made a great effort in this direction - it will not achieve this without first turning a good part of its peasants into proletarians; and then, once caught up in the whirl of the capitalist economy, it will have to endure the inexorable laws of this system, just as the other profane peoples did. That is all. But that is not enough for my critic. He must certainly transform my historical sketch of the emergence of capitalism in Western Europe into a historical-philosophical theory of the general course of development which is fatefully prescribed for all peoples, whatever the historical circumstances they find themselves in, in order to arrive at that economic formation which, with the greatest upsurge of the productive forces of social work, ensures the most all-round development of man. But I ask his forgiveness. (This means too much honor and too much scolding for me at the same time.)
— Seitenzahlen verweisen auf: Karl Marx/Friedrich Engels - Werke. (Karl) Dietz Verlag, Berlin. Band 19, 4. Auflage 1973, unveränderter Nachdruck der 1. Auflage 1962, Berlin/DDR. S. 107-112. Korrektur: 1 Erstellt: 18.07.1999 Karl Marx: [Brief an die Redaktion der "Otetschestwennyje Sapiski"] – Geschrieben etwa November 1877. Nach der Handschrift. Aus dem Englischen.
A sidenote: the often found claim that it was only Werner Sombart who really introduced the word capitalism as late as in 1902 into the German language sphere is clearly false, as phrased, as not only the second edition of Das Kapital quoted above testfies to.
one isolated early attestation of German Kapitalismus, […] from Itzehoe’s Komische Romane (Göttingen: Dieterich 1787, vol. 4, p. 304)
— Franz Rainer: "Word formation and word history: The case of CAPITALIST and CAPITALISM", In: "The lexeme in descriptive and theoretical morphology.", Language Science Press, Berlin, pp. 43–65, 2018. (PDF)
Just look at this debate contribution by Albert Eberhard Friedrich Schäffle: "Kapitalismus und Socialismus", H Lauppsche Buchhandlung: Tübingen, 1870. A work directly cited by Marx himself, including the word capitalism.
Summary
Claim is largely false. It is true that the first volume of Das Kapital doesn't contain the string in German. But it does contain the concept and some editions also used it in translations. It is true that in his works published during his lifetime it is a very rare find. But it is also obvious that he himself 'knew' the word. Ignoring any oral usage, he had not only read it, but commented on it and thus used it himself in writing. Mainly in his letters, but for example also in the manuscripts for the second volume of Das Kapital, where it would still be 'rare' – Engels used it altogether much more often. The claim is further exaggerating greatly a delayed career of the word capitalism in the German language. The implication from the phrasing 'that to Marx the word was unknown and it only became known to the public after 1902' is certainly quite wrong.
On abbreviations used here for sources:
- MEW is the collection of all writings Marx and Engels ever did, but the collection itself got criticised heavily because a socialist influence (that is East-German and Soviet party lines) trumped historical method.
- MEGA is the historical-critical collection, still funded by 'capitalist' German state
Addendum
The passage causing the confusion is
Q I years later however, in 1867 [when Das Kapital was released], the word was still unknown to Marx.
— Translation from the French by Sian Reynolds for William Collins Sons & Co Ltd London and Harper & Row New York 1982, of Fernand Braudel: "Les Jeux de I'Echange", Librairie Armand Colin: Paris, 1979.
The easy way out is here to look at the French original:
Cependant, dix ans plus tard, en 1867, le mot est encore ignoré de Marx.
— Fernand Braudel: "Les jeux de l'échange. Volume 2 of Civilisation matérielle, économie et capitalisme: XVe-XVIIIe siècle", A. Colin, 1979, (p206 gBooks)
Now, being ignorant of any French vocabulary, we consult a dictionary for dix and ignoré:
Verb
ignoré m (feminine singular ignorée, masculine plural ignorés, feminine plural ignorées)
past participle of ignorer
ignorer
to ignore
to be unaware of, to be ignorant of
Thus a better translation is obviously:
However, ten years later, in 1867, the word is still ignored by Marx.
To close the circle: to match the English version given, it would have to read in French approximately: "Cependant, six ans plus tard, en 1867, le mot était encore inconnu de Marx." (Improvement suggestions for style quite welcome)
Which is to say: 'he still did not use it prominently.'
Which seems to be entirely correct for that year.
(That passage is also properly footnoted, btw, significantly weakening and giving appropriate perspective to the strong assertion about Sombart introducing 'that word' only in 1902). Also note: the quote from Proudhon is rendered "capitalism" in the Braudel translation above, but " The land is the fortress of the modern capitalist,[…]" again in English… The original Proudhon reads: "La terre est encore la forteresse du capitalisme moderne , comme elle fut la citadelle de la
féodalité et de l'antique patriciat. link, p223"
A letter switch from six/dix and all important: a suboptimal choice for ignorer. Problem evaporated. To exonerate the translator: the 6/10 is probably not just a translation error but a 'correction' that fell a bit short, it should not have changed 10 to 6 but to 16: the usage of capitalisme by Proudhoun is from his "Idée générale de la révolution au XIXe siècle, …", which was published in 1851.
Now the fun thing to do is tracking down how many English writers cited that passage blindly or even built a nice argument from it…
Braudel is innocent!