Comment by spauldo

AFAIK you all use imperial pints, which are a little bigger than the ones used in countries that still use the customary system (US and I assume Liberia). I'm pretty sure your pints are the same as those used in the rest of the commonwealth, but corrections are welcome.

That goes back to the fact that the imperial system replaced the older customary system after the American revolution. The US legislated a somewhat simplified version of the Customary System the English were using at the time, which was a piecemeal system based on several different acts of parliament over hundreds of years. We (much) later made slight changes so that our measurements are based on metric.

The Imperial System was instituted in the UK in 1826 and most of the measurements stayed the same, which is why our foot and pound are the same as your foot and pound. The biggest change was that imperial simplified the various liquid measurements to make them uniform. Before then, different liquids used different measurements. The gallon used in the US was originally based on the wine gallon whose value had been last set by parliament in 1709.