Against the backdrop of rapid industrialisation and urbanisation of the late nineteenth and early twentieth century, humanitarian concerns about children, especially working-class children, increased in momentum. Reformers introduced new laws that improved children's access to health care and education. In most industrialised countries, schooling became compulsory and the age allowable to leave school was slowly increased. In the Netherlands, the latter was set at twelve in 1900, and in England and Wales it was raised from ten to fourteen in 1918. Reformers were influenced by new theories about adolescence, such as those by American psychologist G. Stanley Hall. In his 1904 work, Adolescence. Its Psychology and Its Relations to Physiology, Anthropology, Sociology, Sex, Crime, Religion and Education, Hall suggests that adolescence, a time of ‘storm and stress’, yet rich with potential, lasted from the ages of fourteen to 24. The way these years were spent would determine the success or failure of the adult-to-be. As such, youth organisations, such as the Boy Scouts, the Girl Guides, and a number of religious and secular youth groups sprung into existence around the turn of the twentieth century to provide children with guidance, protection, and structure during this period of turmoil and difficulty.