In the 1930s a group of researchers descended on the northern mill town of Bolton to observe the natives. They christened their chosen case-study 'Worktown'. It was a ground breaking study of working class culture - and one thing they wanted to know was what makes people happy.

The people of Bolton were asked a simple questions "What is happiness to you and yours?" The letters written in response reveal a snapshot of the innermost thoughts and feelings of ordinary people, living ordinary lives almost a century ago.

Katharine Longworth returns to Bolton to discover whether this town still holds the secret to happiness. Exploring the town centre, markets, pasty shops and pubs; she asks the same question, bringing the original letters to life as modern day Boltonians reflect on the insights of their predecessors.

We knock on the doors of those who live in the same spot as the original correspondents, linking them to the past through the words of the letters, and hearing their own reflections on happiness. Have things changed? Is it more difficult to be happier today? And is Bolton the happiest town on earth?

Original letter written by:

Producer: Katharine Longworth

With thanks to Professor Jerome Carson and Dr Sandie McHugh at The University of Greater Manchester.