 This was the result of the economic decline, as well as advancing engineering techniques which required fewer personnel, along with other factors including the closure of unprofitable factories and coalmines.In March 1976, having just turned sixty years old, Wilson resigned as Prime Minister, ending his leadership of the Labour Party after thirteen years, and a total of nearly eight years as Prime Minister.He was replaced by James Callaghan, who had held senior government positions during both of Wilson's ministries, and had served as a Shadow Cabinet member in the early 1960s.