John Bidwell Mancoe was born in 1895 in Reddersburg in the Orange Free State, he graduated from Healdtown and became a teacher. In 1923 he joined the Industrial and Commercial Workers' Union (ICU), becoming secretary of the Bloemfontein branch and later provincial secretary for the Orange Free State. During the 1930s he was an officer of Clements Kadalie's Independent ICU, centered in East London.
References
Gerhart G.M and Karis T. (ed)(1977). From Protest to challenge: A documentary History of African Politics in South Africa: 1882-1964, Vol.4 Political Profiles 1882 - 1964. Hoover Institution Pres: Stanford University.