This article explores the experiences of unmarried mothers who kept and tried to raise their children between World War One and the end of the twentieth century. It argues that there has not been a simple progression from their experiencing social stigma and ostracism to more enlightened attitudes since the 1970s. Rather there is a great deal that has hitherto been unknown about what the evidence suggests were very diverse experiences and attitudes throughout the period. A major change since the 1970s has been from pervasive secrecy about unmarried motherhood, cohabitation, adultery and similar 'irregular' practices, especially among the middle classes, to greater openness. The article uses a variety of sources, including the records of the National Council for the Unmarried Mother and Her Child (founded in 1918, now One Parent Families), oral histories, contemporary interviews and official and unofficial investigations.