What was the name given to low-cost multifamily dwellings in the cities in the late 1800s?

Low-cost multifamily dwellings in cities during the late 1800s were commonly known as "tenements." These buildings often housed multiple families in cramped and unsanitary conditions, reflecting the rapid urbanization and influx of immigrants during that period. Tenements were typically characterized by poor ventilation, inadequate Plumbing, and limited access to natural light.