OK, the "half-pence", (pronounced hape-nee) was not the smallest coin,
if I remember correctly, after having been here in the USA for 45
years.

I think the 'farthing' was the smallest, or maybe a silver thrupenny
bit. (They used to put these in the christmas pudding as a kind of
good luck charm)

Farthing was a quarter penny. At 240 pence to the pound, you can
imagine how valuable it was.

ISTR that 60 years ago a pound bought you about $4-80