The break between Britain and America made by the American Revolution was neither complete nor final. Intercourse continued and grew across the Atlantic. While America devoted her energies to the settlement of half of the North American continent, Britain began to occupy and develop many vacant portions of the globe. The Royal Navy maintained an impartial rule over the oceans which shielded both communities from the rivalry and interference of the Old World.

The colonisation of Australia and New Zealand, and the acquisition of South Africa in the decline of Holland, created the new and wider British Empire still based upon sea-power and comprising a fifth of the human race, over which Queen Victoria, in the longest reign of British history, presided. In this period moral issues arising from Christian ethics became prominent. The slave trade, from which Britain had so shamelessly profited in the past, was suppressed by the Royal Navy. By a terrible internal struggle, at the cost of nearly a million lives, slavery was extirpated from the United States; above all, the Union was preserved.

The nineteenth century was a period of purposeful, progressive, enlightened, tolerant civilisation. The stir in the world arising from the French Revolution, added to the Industrial Revolution unleashed by the steam-engine and many key-inventions, led inexorably to the democratic age. The franchise was extended steadily in all the Western States of Europe, as it had been in America, until it became practically universal. The aristocracy, who had guided for centuries the advance of Britain, was merged in the rising mass of the nation. In the United States the Party system and the Money Power, which knew no class distinctions, preserved the structure of society during the economic development of the American continent.

At the same time the new British Empire or Commonwealth of Nations was based upon Government by consent, and the voluntary association of autonomous states under the Crown. At the death of Queen Victoria it might well have been believed that the problems of past centuries were far on the highroad to gradual solution. But meanwhile in Europe the mighty strength of the Teutonic race, hitherto baffled by division or cramped in lingering medieval systems, began to assert itself with volcanic energy. In the struggle that ensued Great Britain and the United States were to fight for the first time side by side in a common cause.