"a number of slaves or convicts chained together outdoors doing labor or during transit," 1816, from chain (n.) + gang (n.).
Entries linking to chain-gang
chain n.
c. 1300, "connected series of links of metal or other material," from Old French chaeine "chain" (12c., Modern French chane), from Latin catena "chain" (source also of Spanish cadena, Italian catena), which is of unknown origin, perhaps from a PIE root *kat- "to twist, twine" (source also of Latin cassis "hunting net, snare").
As a type of ornament worn about the neck, from late 14c. As a linear measure ("a chain's length") from 1660s. From 1590s as "any series of things linked together." The meaning "series of stores controlled by one owner or firm" is American English, 1846. The figurative use "that which binds or confines" is from c. 1600.
Chain-reaction is from 1916 in physics; the specific nuclear physics sense is from 1938. Chain-mail armor is from 1795, from mail (n.2). Before that, mail alone sufficed. Chain letter is recorded from 1892; at first usually to raise money; decried from the start as a nuisance.
Nine out of every ten givers are reluctant and unwilling, and are coerced into giving through the awful fear of "breaking the chain," so that the spirit of charity is woefully absent. [St. Nicholas magazine, vol. xxvi, April 1899]
Chain of command is from 1915. Chain-lightning, visible as jagged or broken lines, is from 1834. Chain-smoker, one who smokes one after another, lighting the next from the stump of the last, is attested from 1885, originally of Bismarck (who smoked cigars), thus probably a loan-translation of German Kettenraucher. Chain-smoking (n.) is from 1895.
gang n.
from Old English gang "a going, journey, way, passage," and Old Norse gangr "a group of men, a set," both from Proto-Germanic *gangaz (source also of Old Saxon, Old Frisian, Danish, Dutch, Old High German, German gang, Old Norse gangr, Gothic gagg "act of going"), of uncertain origin, perhaps from PIE root *ghengh- "to step" (source also of Sanskrit jangha "shank," Avestan zanga- "ankle," Lithuanian žengiu "I stride"). Not considered to be related to go.
The sense evolution is probably via meaning "a set of articles that usually are taken together in going" (mid-14c.), especially a set of tools used on the same job. By 1620s this had been extended in nautical speech to mean "a company of workmen," and by 1630s the word was being used, with disapproving overtones, for "any band of persons traveling together," then "a criminal gang or company" (gang of thieves, gang of roughs, etc.). By 1855 gang was being used in the sense "group of criminal or mischievous boys in a city." In American English, especially of slaves working on plantations (1724). Also formerly used of animal herds or flocks (17c.-19c.). Gangway preserves the original sense of the word, as does gang-plank.