how did import restrictions started?

Answer 1

They started to protect the businesses here in the USA, so we would not be flooded with products from other countries that were made at a cheaper price.

They were also made so diseases from animals, plants, eg. would not come in and harm the public.

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http://www.eurunion.org/partner/steelletter.htm

http://www.heritage.org/research/energyandenvironment/EM265.cfm

http://www.customs.govt.nz/travellers/arriving+in+new+zealand/import+restrictions/default.asp

http://www.michigan.gov/emergingdiseases/0,1607,7-186-25806-73145--,00.html

Answer 2

Import restriction is a method of protecting? the public. It was originally intended for disease control and to limit imported insects, animals etc. that could damage our ecosystem. It is much more commonly used now to punish someone our pols dont like, protect jobs that Americans are no longer competitive at or to raise money (import taxes). I am a firm believer in free trade, whoever does it best wins.