For as long as modern trade has existed, there have been tariffs – duties, levies or taxes – that have been applied to goods entering a country.
Early in the 19th century, the English economist David Ricardo introduced his Theory of Comparative Advantage. The theory posits that countries benefit from foreign trade by specializing in and exporting goods where they have a relative advantage, even if they are not the most efficient producers of those goods. In other words, trading freely would help countries and their peoples prosper. The argument was a strong counter to the mercantilist dogma of the day. Mostly free trade brought unprecedented prosperity to Great Britain, propelling it into the rank of first amongst nations.