Train hopping is a practice in which people board trains, typically freight trains, by stealth in order to hitch a free ride to the train's destination. It has been around for about as long as trains have, with documented instances of people hopping trains to get home after the conclusion of the Civil War in the United States, suggesting that the practice was well-established. Many people associate this practice with the hobo community, and many train hoppers are vagrants or wanderers. This method of transportation is extremely dangerous and illegal in most regions of the world.
You may also hear train hopping referred to as freight hopping, referencing the types of trains classically used by train hoppers. To hop a train, people generally familiarize themselves with the routes and trains in an area so that they can pick a train which will move them along on the path to their destination. Trains are classically boarded before they start moving for safety, although some train hoppers will leap onto a moving train. Once the train gets going, the train hopper remains hidden to avoid detection, and he or she tries to stay hidden until the destination is reached.
In the 1930s, train hopping grew to be a very popular method of transportation. The global economy was down, leading some people to seek employment as itinerant workers, and especially in the United States, workers had to cross a lot of ground to find new jobs. Hopping a train was one way to accomplish this, and the practice became widespread, with thousands of people riding the rails illegally every day.
Train hopping also experienced a revival in the 1950s and 1960s, when members of the counterculture movement started seeing it as a form of personal expression. However, it began to go into decline after this period for several reasons. One of the key issues was the advent of containerization: there's nowhere to stow away on a shipping container. The boxcars classically used to load freight were abandoned, reducing the available cars to stow away on. The use of trains for freight also went into decline with aircraft and trucks entering widespread use, thus reducing the number of trains available for hopping.
This method of train travel does still endure; although it isn't as widely practiced as it once was. Vagrants continue to train hop in some regions of the world, and anarchists sometimes also travel via train hopping, expressing solidarity with the vagrant lifestyle. In either case, train hoppers work hard to avoid the railroad police officer, also known as the “bull,” and increasingly they avoid rail crews as well since crews are not as supportive of the practice as they once were.