Shotgun is a style of residential architecture that is best known in the southern United States; particularly in New Orleans.

A shotgun house is long and narrow; often no more than twelve feet wide (3.7 meters). The rooms in this linear layout are arranged in a row, one behind the other, as there is no space for hallway. This layout lacks in privacy, as you must walk through a bedroom or two to reach the kitchen, which is usually found at the back of the house. Many of these homes were built without bathrooms. Sometimes, a second floor was added, as well as a hallway and interior bathroom. In other cases, a bathroom was added on to the rear of the building. By the middle of the last century, these houses were associated with poverty and many were later destroyed during urban renewal efforts. Nevertheless, many remain in use.

Read more about this style on Wikipedia, HERE.