I'll admit what I posted was from memory. That includes remembering that the US seemed strongly inclined to disdain GSM as a system and that the third GSM band was added partly because the second clashed with other US cell-phone tech. But both facts might well be distorted.
OTOH, I do recall the multi-system craziness in the US was widely regarded as the height of lunacy. :-)
Analog in AU was AMPS. If it isn't switched off yet, then it nearly is because GSM licenses were issued with a guarantee that the AMPS system would be switched off on Jan 1, 2001 (there was a legal challenge to the switch off).
Wade.