I'm not an expert on manufacturing locations - and probably someone will come along with a more definitive answer. However to the best of my knowledge Canon does not make any lenses in the USA. So-called USA lenses are packaged for sale in the USA, but are not made here nor are they any different than lenses packaged for sale elsewhere.
My copy, purchased new this year from Best Buy when they were the same price as the Refurbished store, was made in Japan. Anecdotal, but you can always ask the retailer- it's printed on the outside of the box, after all.
