My grandparents lived in a little shotgun house when they got married in 1928. It was what they could afford. They eventually had a larger house that my grandfather and his brother built, but for a little while, they lived in a shotgun house.
Many people have added on to their shotgun houses, but if you travel nearly anywhere in the rural South, where there are still a lot of pre-1940 homes around, you will see shotgun houses. A lot of the homes in mill villages were of the shotgun variety. They didn't take up a lot of space and were cheap to build.