Green’s Dictionary of Slang

Bolivian marching powder n.

also Bolivian brain food, Bolivian flake, Bolivian marching powder, Columbian marching powder
[Bolivia, like Colombia, is a major source of cocaine]

(drugs) cocaine.

[US]R. Sabbag Snowblind (1978) 13: The Bolivian brain food they had ingested was only one course in a sublime international feast.
[US](con. 1982–6) T. Williams Cocaine Kids (1990) 41: Some of the best cocaine comes in flakes, not rock, like Bolivian flake.
[Aus]P. Temple Black Tide (2012) [ebook] Nicotine, dope, hash, barbiturates, speed, acid, smack, Columbian marching powder [...] all entered the massive frame by some route.
[US]G.V. Higgins At End of Day (2001) 31: If capsules ain’t around, then the Dravon and Dilaudid, an the bags of marching powder.
[UK]Fabian & Byrne Out of Time (ms.) 191: Caplan was eyeing the tiny folded rectangle that I had placed on the table. ‘Is that my Bolivian marching powder?’.
[UK]Guardian Weekend 23 Oct. 119: The coke was Novocaine injected into my gums, not the Bolivian marching powder.
[Aus]L. Redhead Cherry Pie [ebook] ‘In the unlikely event I ever get hitched it’d take place in Vegas with [...] a shitload of Bolivian marching powder’.
[UK]K. Sampson Killing Pool 59: Lance Campion’s strategies [...] to flood this land with Bolivian marching dust.