Cabooses are one of the most recognizable cars on trains. This is partially due to the standard design of the car with its center tower with windows on all sides. Most notably though cabooses are the last car in a train.
These cars had a dual purpose. First of which is that cabooses housed the train workers while they were in transit, providing them with beds and small kitchen facilities. The second purpose of the caboose was to provide train people with a key vantage point. From the top window in the caboose, the workers could see the entire length of the train. This allowed them to check for problems on the train. The primary example is that from the caboose the train workers could see fires on rails which arose from too much friction between the track and the train's wheels. If fires arose workers in the caboose could signal the conductor to stop the train and they could address the issue. Caboose thus was invaluable to the operations of trains.
The caboose housed in Martinsburg Roundhouse was built circa 1913 for the Baltimore and Ohio Railroad Company.