“Once, as Mung went his way athwart the Earth and up and down its cities and across its plains, Mung came upon a man who was afraid when Mung said: “I am Mung!”
And Mung said: “Were the forty million years before thy coming intolerable to thee?”
And Mung said: “Not less tolerable to thee shall be the forty million years to come!””

Source: The Restaurant at the End of the Universe

Shall Earth No More Inspire Thee (May 1841)

Source: Three Men in a Boat

1840s, Past and Present (1843)

Of Solitude, vii; reported in Bartlett's Familiar Quotations, 10th ed. (1919).

Source: Way Station (1963), Ch. 35

The Intelligent Woman's Guide To Socialism, Capitalism, Sovietism, and Fascism (1928)
1920s
Context: It is far more likely that by the time nationalization has become the rule, and private enterprise the exception, Socialism (which is really rather a bad name for the business) will be spoken of, if at all, as a crazy religion held by a fanatical sect in that darkest of dark ages, the nineteenth century. Already, indeed, I am told that Socialism has had its day, and that the sooner we stop talking nonsense about it and set to work, like the practical people we are, to nationalize the coal mines and complete a national electrification scheme, the better. And I, who said forty years ago that we should have had Socialism already but for the Socialists, am quite willing to drop the name if dropping it will help me to get the thing. What I meant by my jibe at the Socialists of the eighteen-eighties was that nothing is ever done, and much is prevented, by people who do not realize that they cannot do everything at once.

Anecdotes
Source: A New Zealand Dictionary of Political Quotations, p. 94.

Source: Aphorisms and Reflections (1901), pp. 58-59