>A plant in, say, Kansas, is a couple of days of UPS Ground from a huge portion of the country.

80% of the US population lives east of the 100th meridian, which bisects Kansas.

It's probably not best to optimize for the lowest maximum ship time in the lower 48, but something more weighted for population. Lowest average transit time. I would have guessed something like Nashville, TN. Claude is telling me Nashville is up there but Dayton, OH is the best. 14% <= 1 day, 46% reached in <= 2 days and 74% reached in <= 3 days. 2.83 average.

Compared to Kansas City, KS at 5%, 25%, 61%. 3.11 average.

This fab is in South Deerfield, MA which is 15%, 26%, 52%, 3.32 avg.

I guess population is also technically not the best measure. It would be better to measure the potential customers. Which is interesting because those are going to be skewed towards the coasts to some degree.

Maybe your Kansas suggestion is more correct than I thought. I'd still wager its more like the midwest than the plains though.

The big advantage Kansas has is a living wage is lower. That probably isn't the biggest bottleneck in this case though.