> In general banknotes have their design changed every 10-20 years, and very old banknotes are no longer legal tender IIRC, the US has never declared any versi

> In general banknotes have their design changed every 10-20 years, and very old banknotes are no longer legal tender IIRC, the US has never declared any version of its old currency not-legal-tender, and no-one would have any problem spending any US banknote that in any way resembles the current ones in size or shape.