You may have already contemplated this, but just to begin with some additional precision, Marx envisioned a proletarian revolution, and not just a revolution tout court. Definitionally then, you won't see a proletarian revolution in a nation that hasn't industrialized and developed a proletarian class.

The reason that Marx envisioned a specifically proletarian revolution has to do with his understanding and analysis of society. For purposes of answering this question, one of the, if not the kernel, of Marx's analysis might be summed up by this passage from Volume III of Capital: "The specific economic form in which unpaid surplus labour is pumped out of the direct produces determines the relationship between those who dominate and those who are in subjection... Upon this [economic form], however, is founded the entire organisation of the economic community which grows up out of the production-relations themselves, and thereby at the same times its specific political form... [It is this economic form] which reveals the innermost secret, the hidden foundation of the entire social structure..."

To put it concisely, there is a primacy to the specific economic relations of a society that determines in part many other aspects of that society. Hence, you will often see (for instance, in The German Ideology) Marx discussing tribal, ancient, feudal, and capitalist societies as if this were a very natural way of categorizing societies. (I think it is, but some might disagree.)

In any case, it is through this specific categorization of societies that Marx believes allows us to understand how societies have transformed through the ages from one sort of system of economic relations to another. Certain economic relations solve certain problems, but also engender their own problems that become solved by different economic relations. G.E.M. de Ste. Croix gives such an analysis of the classical Greek and Roman world. In order for their economies to grow, more and more slaves had to be acquired, which required territorial expansion, but territorial expansion soon became far too costly, and so in order to acquire more slave labour, slaves were bred. This however meant a contradictory decrease in slave efficiency. In response, previously free men were increasingly exploited, turning the classical world from a slave society into a feudal society.

Under Marx's analysis, socialism is a specific response that is developed from the specific problems that a capitalist society engenders by being a capitalist society. As Engels writes on the specific matter of Russia and revolution: " it is an historical impossibility that a lower stage of economic development should solve the enigmas and conflicts which did not arise, and could not arise, until a far higher stage. All forms of gentile community which arose before commodity production and individual exchange have one thing in common with the future socialist society: that certain things, means of production, are subject to the common ownership and the common use of certain groups. This one shared feature does not, however, enable the lower form of society to engender out of itself the future socialist society, this final and most intrinsic product of capitalism. Any given economic formation has its own problems to solve, problems arising out of itself; to seek to solve those of another, utterly alien formation would be absolutely absurd. And this applies to the Russian commune no less than to the South Slav zádruga, the Indian gentile economy or any other savage or barbaric form of society characterised by the common ownership of the means of production."

Bibliography:

Here's a piece by Engels specifically on the issue of revolution in Russia. (http://marxists.catbull.com/archive/marx/works/1894/01/russia.htm)

Here's the famous opening to The German Ideology. (https://www.marxists.org/archive/marx/works/1845/german-ideology/ch01a.htm)

I had cited a passage from Volume 3 of Capital.

I also recommend The Class Struggle in the Ancient Greek World by G.E.M. de Ste. Croix which not only performs a very clear and precise, analytical expounding of Marx's theory, but applies it to the slave economies of the classical world.

You may be interested in the works of the Frankfurt School a collective of philosophers, psychoanalysts, and sociologists who initially convened to understand why the Socialist aspects of the German Revolution of 1919 were rejected. A large part of their work focused on the ideas of "alienation" and "class consciousness" - with probably their most well known work being Horkheimer and Adorno's Dialectics of Enlightenment.

Essentially (as QFlux highlighted nicely) Marx viewed the proletarian revolution as being only a matter of time, a natural evolution of the oppression of Capitalism - which itself is inherently a self-destructive machine. When the Bolsheviks seized power following the October Revolution their job, as they saw it, was to hold power until the revolution from abroad came to their assistance. At the Third Congress of Soviets Lenin noted as such;

"We never flattered ourselves with the hope that we could reach the end without the aid of the international proletariat...Of course, the socialist idea cannot be attained in one country alone...[Yet] we can see how the socialist revolution is ripening in every country of the world by hours and not by days..."

Indeed this is where we see the difference between Marxism and Bolshevism - the Bolshevik interpretation of Marxism. The Bolsheviks, as often quoted, believed themselves the "vanguard of the proletariat", which in essence highlighted a seizure of power and transfer into the "Dictatorship of the Proletariat" followed by mass industrialization of the country. When Marx wrote the Communist Manifesto he intended it for highly industrious nations such as Britain or the United States.

As to why it never took hold in those industrious nations, is where members of the Frankfurt School stepped forward. Marx himself mentioned the concept of Alienation frequently, but only rarely referred directly to the concept of 'Class Consciousness'.

Marx asserted that, at its best, work is what makes us human. It fulfills our Gattungswesen - “Species Essence”; it allows us to live, to be creative, and to flourish. Through using labor as a mode of both self expression and sustenance - the worker has, in a sense, married what we now see as two modes of existence completely and utterly removed from each other. We would have begun to use production as a means to solidify our personality, individuality, and character into that which we are producing. Alienation was the divorce of personal expression in labor and labor itself - creating 'work' and 'life' as two expressly different modes of existence. The former being done to afford the latter. The development of the assembly line was something Marx expressly pointed out as being the crux of alienation; a seemingly endless set of monotonous, repeated tasks carried out for hours on end. It was his opinion that alienation of labor would inevitably lead to a universal 'class consciousness' in which the international proletariat would become aware of their collective subjugation at the hands of the bourgeoisie, and would resolve to overthrow them and seize the means of production.

We now know that never totally happened, and the Frankfurt School - in its exodus to America in the interwar period - collectively wrote a number of books and works on aspects as to why this never happened. A prevailing theory was a continuation of what Marx had called 'false class consciousness' - the active illusion put on by the bourgeoisie to convince the collective proletariat that the means of controlling Capitalism were far out of their reach. Dialectics of Enlightenment chiefly described this in the context of America's (and to a larger extent, the West's) Consumerist Culture which boomed following the end of World War II. Commodity fetishism led the worker to be distracted and even lulled into comfort - not willing to risk throwing away what security and possessions they had for an abstract concept such as Marxism or Socialism.

I have not read it myself, but I understand that Louis Hartz's The Liberal Tradition in America is a work over-viewing the general difference between politics in America as opposed to Western Europe and how American politics have tended to skew away from liberal leanings.

Bibliography:

I had mentioned Dialectics of Enlightenment by Max Horkheimer and Theodor Adorno

Stuart Jeffries' Grand Hotel Abyss is a good collective biography on the group as well as a general outline of their beliefs.

Ronald Grigor Suny's The Soviet Experiment: Russia, the USSR, and the Successor States is a brilliant work on the development of Soviet Communism in the wake of Imperial Russia and thereafter. Much of what I mentioned on Soviet Communism and the Lenin quote are from this book.

My copy of the Hackett Publishing Company's Marx: Selected Writings contains a plethora of Marx's writings in rough chronological order, including On the Jewish Question, Theses on Feuerbach, Economic and Philosophic Manuscripts of 1844, and of course The Communist Manifesto which I drew most of my content from.

There have been some answers in this thread already, I will take a somewhat different approach.

Quite simply, Marx was just wrong about Capitalism. Much analysis has tried to explain this question but many tie themselves into knots to avoid admitting that simple fact. The worker classes in the developed countries did not get poorer and poorer, but rather got richer and richer. The Capitalist countries did not get more and more dictatorial but rather more and more democratic. The increase in commercial society pushed along social democracy, the socialist parties demanded more protection and a social state, and they started to receive it. The socialist parties, by WW1, were insiders, most of the base, nationalistic, violent revolution was simply not going to happen in these states.

Another factor is that Socialism was simply a much weaker force than many he and others expected. The socialist/communist parties completely failed to act together against the WW1. The parties were more interested in gaining more political influence in their own countries, and the base was far more driven by nationalism and the desire for incremental improvement, there are very few true socialist, most were simply people who saw socialism as a way to get a bigger slice of the pie, if they could get it within the capitalist system, the were more or less content. Many of the socialist parties split into multiple parties over this issue.

/u/Rockdigger is right that there never was much 'Class Consciousness'. The explanation that "the active illusion put on by the bourgeoisie" frankly says more about their own bias and failure to understand then about the workers. The workers are not to stupid, they have not been confused by the bourgeoisie, like everybody else they simply understand what is in their own self interest. Many understand that burning down the existing system and creating some shot at utopia will not actually improve their lives, the workers were correct in that assessment, it is the socialist thinkers who were the ones who did not understand.

It happened in Russia because Russia had a backwards regime that refused to modernize and build a modern mass politics base. There was a base to be had, the rightist parties had huge numbers and there was a huge amount political organisation in favor of the Zar. The Regime failed to take advantage of this, they essentially failed to slowly relieve the pressure over time. They should have gone the route of the This was possible feasible before the war but the cracks were there and ready to be exploited.

Even then, it was not actually socialist that overthrew the regime. It was essentially political insiders that made a deal to finally achieve the needed changes. These changes however were far too late, and things went out of control. In the disorder that happened afterwards it was a** struggle for political power and who would come out victorious would be determent by who used it resources most effectively, and not who has the best political philosophy.** Even within Socialism the Left SR or the Mensheviks could have won, had the been smarter. Many other groups could have come out on top, it just happens that the right combination and resources and leadership.

People always talk about this socialist revolution but there were really two revolutions, one in the city and one in the countryside. In the country the reason for revolution was always the same, land. The success and eventual control that the worker had, was only because they did not oppose this second, and in many ways far more powerful revolution.