According to a book that I read recently, about crime in Eighteenth Century England, many young men, like the protagonist of this song 'took to the highway' because of the apprenticeship system. Apprentices were bound to their masters for seven years, during which time the master fed, clothed and housed them in return for teaching them a trade. But if during that time the apprentice got a girl pregnant or got married ("at seventeen-o I took a wife and I loved her dearly as I loved me life")he broke the terms of his apprenticeship and could find himself out on the street. Sometimes the only way to survive and to support a family was a life of crime.