The 'Card' in question is Edward Henry Machin - his mother called him 'Denry.'
This light-hearted story is of his rise from humble beginnings as the son of a washerwoman and sempstress in the last quarter of the nineteenth century, in the pottery towns (which Arnold Bennett christened 'The Five Towns') of the English Midlands; how, by his own wits, enterprise and 'nerve' he rose to wealth, married bliss and public recognition as the youngest-ever mayor of his home town.
"'And yet,' demanded Councillor Barlow, 'what's he done? What great cause is he identified with?' 'He's identified,' said the speaker, 'with the great cause of cheering us all up'."