hub (n.)

"solid center of a wheel," 1640s, of uncertain origin, perhaps, if all the senses are in fact the same word, from hubbe, originally probably "lump, round protuberance, boss," the source of the hob of a fireplace and the hobnail of a boot. A wheelwright's word, not generally known or used until c. 1828; it reached wider currency with the vogue for bicycling. Meaning "center of interest or activity or importance" first recorded 1858 in writings of Oliver W. Holmes, and originally especially of Boston.

Boston State-House is the hub of the solar system. [Holmes, "Autocrat of the Breakfast Table"]

[E]verybody knows that Boston used to be called the Hub, meaning the hub of the universe. It may still be the hub, because the center of a wheel moves slowly. [J.P. Marquand, Life magazine, March 24, 1941]