European nations had regarded American trade as a profitable field of enterprise and as probably responsible for much of Great Britain's prosperity. It was therefore a relatively easy matter for the United States to enter into commercial treaties with foreign countries. These treaties, however, were not fruitful of any great result; for, "with unimportant exceptions, they left still in force the high import duties and prohibitions that marked the European tariffs of the time, as well as many features of the old colonial system. They were designed to legalize commerce rather than to encourage it."* Still, for a year or more after the war the demand for American products was great enough to satisfy almost everybody. But in 1784 France and Spain closed their colonial ports and thus excluded the shipping of the United States. This proved to be so disastrous for their colonies that the French Government soon was forced to relax its restrictions. The British also made some concessions, and where their orders were not modified they were evaded. And so, in the course of a few years, the West India trade recovered.