Many US states either have no sales tax or a restricted sales tax. Delaware is an example of the former, Pennsylvania of the latter. Pennsylvania, for example, charges no tax on food, other than food intended to be consumed on premises, or on clothes, except for that intended for a special purpose (like swimsuits).
It's something to consider if you find yourself near an outlet mall or a big box store in those states. There is for example, a relatively new outlet mall just off I-79 at the Meadow Lands exit near Canonsburg.