They believed that the immigrants were hurting Americans(more strictly, immigrants that were not descendants of the original 13 colonies). A significant example is the Know Nothing or American Party of the 1850s. An earlier example is the Federalist Party which extended the time required to be American to 14 years through the Alien and Sedition Acts.
Mexico offers much greater job opportunities in the cities and maquiladros by the U.S-Mexico border, so many from the more poverty-stricken, rural countries of central america travel to Mexico for a better living or to send remittances back to their families.
Answer: However bad the Continental System was for Britain, it was disastrous for Napoleon because it backfired on him. French custom' revenue fell and European nations were starved of British colonial goods: coffee, sugar, tobacco, cocoa, and cotton textiles. Apart from cotton, the imported goods were addictive luxuries and people resented the French depriving them of these commodities. Replacement items such as sugar beet and linen were not tolerated. The British blockade of European ports and the scarcity of goods created a rise in European nationalism.
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