In 1831, Lord Byron brought his Industrial Radical Party to power in the political vacuum following the Duke of Wellington's assassination, despite an 1830 coup d'etat led by Wellington in an attempt to prevent the acceleration of technological change and subsequent social upheaval. As a result, the Tory Party was eclipsed, along with its hereditary peerage. As a result, British trade unions were co-opted to assist the ascendancy of the Industrial Radical Party, much as they were by the Labour Party of Great Britain in our own world during the latter half of the twentieth century. However, the Luddite anti-industrialist working class revolutionaries were ruthlessly suppressed.
Babbage Difference engines and Analytical Engines become mass-produced and ubiquitous. Their use emulates the innovations which actually occurred during our information technology revolution. The novel explores the social consequences of information technology revolution during the nineteenth century, such as the emergence of clackers (a reference to our own hackers), technically proficient people skilled at programming the Engines through the use of punch-cards, such as Théophile Gautier.
In the novel, the British Empire is more powerful than it was in our world, thanks to the development and use of extremely advanced mechanical computer-controlled steam-driven technology in industry and in the military, with airships, dreadnoughts, and artillery dominating the battlefield. and the Babbage computers themselves. Britain, rather than the United States opened Japan to Western trade, in part because the United States became fragmented, due to interference from a Britain which foresaw the implications of a unified United States on the world stage. Counterpart successor states to our world's United States include: a (truncated) United States; the Confederate States of America; the Republic of Texas; the Republic of California; a Communist Manhattan Island commune (with Karl Marx as a leading light); British North America (analogous to Canada, albeit slightly larger in this world); Russian America (Alaska); and terra nullius, or "no man's land". All lands in the Americas are colloquially referred to as America (viz. Sybil: "Do you know anything about Texas, Hetty?" Hetty: "A country in America. French own it, don't they?")
Napoleon III's French Empire holds an entente with the British, and Napoleon is even married to a British woman. In the world of The Difference Engine, it occupies Mexico. Like Great Britain, it has its own analytical/difference engines, especially used in the context of domestic surveillance within its police force and intelligence agencies.
As for the other world powers, Germany remains fragmented, with no suggestion that Prussia will eventually form the core of a unified nation as it did in our own world in 1871, which may be due to French sabotage analogous to that pursued in the case of the fragmentation of the United States noted above. As noted above, Japan is awakening after the British ended its isolation, and looks set to become one of this world's leading industrial and economic powers from the twentieth century onward, as in our world. Due to Lord Byron's and Babbage's intervention, the Irish potato famine never occurred, and as a result there is no mention of agitation for Irish home rule or Irish independence.
Among other historical characters, the novel features "Texian" President Sam Houston, in exile after a political coup in Texas, a reference to Percy Bysshe Shelley (as a Luddite), John Keats as a kinotropist (an operator of mechanical pixelated screens), and Benjamin Disraeli as a publicist and tabloid writer.
Under the Industrial Radical Party, Britain shows the utmost respect for leading scientific and industrial figures such as Isambard Kingdom Brunel and Charles Darwin. Indeed, they are collectively called "savants" and often raised to the peerage on their merits, causing a break with the past as regards social prestige and class distinction. These new patterns are also reflected in the educational sphere: classical studies have lost importance compared to more practical concerns such as engineering and accountancy.