When did indoor bathrooms become available to the common ma?

Indoor bathrooms began to become more common in the late 19th century, particularly in urban areas, as advancements in Plumbing and sanitation were made. By the early 20th century, many middle-class homes in developed countries were equipped with indoor bathrooms. However, it wasn't until the post-World War II era that indoor plumbing and bathrooms became standard in most homes, including those of the working class. The widespread adoption varied significantly by region and socioeconomic status.