Public sewers have served a vast majority of America's homes since 1970. Almost all other homes have used a septic tank or a cesspool. Only a tiny percent had neither a public sewer, septic tank, or cesspool in recent decades. However, look at individual States. As recently as 1970, a number of States, primarily in the South (plus Alaska), had fairly large percentages of units (10 percent or more) using other means of sewage disposal. These other means would generally be a privy, a chemical toilet, or facilities in another building. By 1990, only Alaska still had a high percentage of such units.
But, how about the more distant past? Data on sewage disposal for all housing units was first collected in 1970. However, if we use an earlier item on toilet facilities, we can journey back to the first housing census in 1940.
As recently as 1950, a quarter of America's homes had no flush toilet, with some States topping 50 percent!
In 1940, over a third of the homes had no flush toilet, with some States over 70 percent! Of the 13 million units reporting no flush toilet in 1940, 11.8 million had an outside toilet or privy, another one million had no toilet or privy, while the small remainder had something called a nonflush toilet in structure.
Mississippi provides an excellent portrait of this change in America's housing over the decades. About 80 percent of its homes had no flush toilet in 1940; by 1990 a mere 4 percent lacked a public sewer, septic tank, or cesspool.