Green’s Dictionary of Slang

Camptown n.

[? song ‘Campdown Races’/‘Campdown ladies’ (Stephen Foster 1850); lyrics offer no direct reason, though chorus ‘Gwine to run all night! Gwine to run all day!’ might suggest using money to buy liquor]

(US) a collection of money.

[US]Life in Boston & N.Y. (Boston, MA) 14 Apr. n.p.: At about 11 o’clock the bubs took up a ‘Camptown’ to buy a quart of r.g., and soon raised twenty-five cents.