The InterRail Pass was introduced in 1972 to celebrate the 50th anniversary of the International Railway Union's (Union Internationale des Chemins de Fer). Youth under 21 years old were offered to travel for one month in 21 member countries at a very low cost, less than 30 British pounds or about 50 U.S. dollars.
About 5,000 young people bought the InterRail Pass in 1972, and it was so popular that it was repeated in 1973, when about 85,000 young travelers bought the card. Over the years, the InterRail Pass had expanded its reach to more and more countries, while the travel offers has become more varied and even includes First Class travel. Outside Europe the card is known as the Eurail Pass.
For most young people traveling with the InterRail Card/Pass in 1973 was very, very different from how you travel today. Most kids traveled without credit cards, cellphones, Internet, Web, Facebook, WiFi, guidebooks and with very little money. If you couldn't find a campground or a bed in a youth hostel, you had to sleep on a night train, on a beach, with a friend, on a railway station or wherever you found a place to rest your head. It was not always safe, but kids who had come of age in 1968 didn't worry much about safety. They were naive and willing to take risks. And most of them made it home alright.