1/4 Real 'Quarto/Quartilla'

Durango issued copper fractional coinage during the 1860s largely because the federal government in Mexico City had effectively lost the ability to enforce monetary uniformity — the Reform War and the French Intervention had shattered central authority, leaving individual states to fill the gap in small-denomination currency however they could. The quartilla existed to serve daily market transactions that silver simply couldn't reach at practical scales.

KM#349 is specific to 1866, a year in which Maximilian's imperial administration was already visibly faltering, with French troop withdrawals imminent following U.S. pressure after the end of the Civil War.