The word 'hub' as an effective center
The first metaphoric use of hub to mean a center of activity or interest occurs in an essay by Oliver Wendell Holmes collected into The Autocrat of the Breakfast-Table in 1858:
Boston State-House is the hub of the solar system. You couldn’t pry that out of a Boston man, if you had the tire of all creation straightened out for a crowbar. — p. 120.
Shortened to The Hub and robbed of most of its irony, it became a nickname for Boston still used today.
From there, it was used in a more general sense for other cities:
Having for its starting point the central city [St. Louis],the destined commercial hub of the continent taking its course to the sea, and spreading its many branches as it advances, until it taps every commercial artery of the South… — L. U. Reavis, Saint Louis, the Commercial Metropolis of the Mississippi Valley, 1874.
In the late 1880s, the somewhat more literal notion of a railway hub arose:
If all these plans are carried out Winnipeg will speedily be a railway hub in earnest, receiving not only the Canadian Pacific and the Northern Pacific, but an array of the wealthiest and most progressive railways upon the continent… — Railway World 32 (1888), 471.
The Railway Hub and Commercial Centre of the Dakotas, Aberdeen is now the leading business and Railway City of the two Dakotas… Advertisement, Scribner’s, 1889.