A lot of that will depend on where you are and where you're shopping. For example: even in the Bay Area it can be hard to find garlic grown outside of China despite Watsonville and Fresno growing a ton of garlic. American-grown ginger as well can be extremely difficult to find as well. Same with avocados and limes. The Southern Californian climate is well suited to both avocados and limes, but most I've found out here are sourced from Mexico or South America (except for the 'specialty' avocados).
It helps that the food doesn't have to travel far from where it's grown. Sadly, the majority of the planet isn't as fortunate.