CULLOM, Ill. — Hack Street isn’t exactly Michigan Avenue. The main thoroughfare of downstate Cullom — a town of around 600 about halfway between Bourbonnais and Bloomington — showcases cement geese hand-molded by the mayor and a market often staffed by one clerk. But don’t confuse a quiet town with a dead one. Cullom’s business center is crowded, its high school enrollment is stable, and most homes here are occupied, so trying to buy one can be difficult. Rural towns like Cullom stand in contrast to some larger downstate communities that have struggled amid population loss and a changing natio...