It was a mining town for many years but by 1370 DR the mines were no longer profitable and the population dwindled to about 100 souls. It became known for its mushrooms, which grew in some of the old mines.
During the reign of King Foril I, mining resumed and the population expanded fivefold. Minroe was reputed to have high quality jewelers and gunsmiths who provided their products at affordable rates. It also remained known for it's mushrooms which still grew in some of the mines.
Dragon 365 Backdrop Cormyr (pg 48).
Volo's Guide to Cormyr tsr9486, 1995, (pg 125).