#and it Definitely isn't mentioned in any pre-1840s contexts at least in any secondary literature

[lesamis]

mary shelley is really so extraordinary. "little england" & "little englandism" became an entire political discourse in the late 1800s (best as i can tell from c. 1870 onwards) & denoted those - often, not always, anti-imperial - thinkers who advocated for economic isolationism and wanted to limit the british empire's expansion, administration, and aggression, maintaining that england was best when contained to its own borders. the term is still in use - nowadays in brexit contexts - and was throughout the entire twentieth century.

it is also, in much the same sense in which it'd come to be used fifty years after the novel's publication, somehow in The Last Man - which shelley finished writing in 1826.

The plague was in London! Fools that we were not long ago to have foreseen this. We wept over the ruin of the boundless continents of the east, and the desolation of the western world; while we fancied that the little channel between our island and the rest of the earth was to preserve us alive among the dead. It were no mighty leap methinks from Calais to Dover. The eye easily discerns the sister land; they were united once; and the little path that runs between looks in a map but as a trodden footway through high grass. Yet this small interval was to save us: the sea was to rise a wall of adamant—without, disease and misery—within, a shelter from evil, a nook of the garden of paradise—a particle of celestial soil, which no evil could invade—truly we were wise in our generation, to imagine all these things! But we are awake now. The plague is in London; the air of England is tainted, and her sons and daughters strew the unwholesome earth. And now, the sea, late our defence, seems our prison bound; hemmed in by its gulphs, we shall die like the famished inhabitants of a besieged town. Other nations have a fellowship in death; but we, shut out from all neighbourhood, must bury our own dead, and little England become a wide, wide tomb.