1560s, "one who is employed in manual labor, one who works mechanically, a handicraft worker, an artisan," from Latin mechanicus "of or belonging to machines or mechanics," from Greek mekhanikos "an engineer," noun use of adjective meaning "full of resources, inventive, ingenious," from mēkhanē "device," from PIE *magh-ana- "that which enables," from root *magh- "to be able, have power."
Their social and professional organizations were prominent late 18c. and early 19c. in Britain and America, and account for the Mechanics Halls in many towns and the Mechanicsvilles and Mechanicsburgs on the map. The sense of "skilled workman who is concerned with the making or repair of machinery" is attested from 1660s, but was not the main sense of the word until the rise of the automobile in late 19c.