Country-of-origin labeling has been required of all goods imported into the US since the 1890’s, originally as part of the McKinley Tariff Act. Around the time of WWI, the law was updated to require the words “Made in <country of origin>” (Thanks, Antiques Roadshow!)
I’ve no idea what the specific sanctions would be for importing mislabeled or unlabeled goods – fines and/or seizure of the goods, I would imagine.
There’s currently an ugly fight going on in agricultural/food industry circles over implementing the 2002 Farm Bill, which requires Country of Origin Labeling (COOL) for meat, produce and other agricultural commodities.