Rise of Nations is for Mac

http://www.amazon.com/Rise-Of-Nations-Gold-Mac/dp/B0002ITT84/

I realise it's quite expensive, but you could always yar-harr it.

Many people call it the best RTS ever made.

It has the same principles of Empire Earth, going from the Ancient age to Present day, and it's real time strategy like Empire Earth/Age of Empires but with a cities concept like Civilisation.

The gamespot review really summarises the game to be honest.

I'm convinced that this is what you're looking for.