When friends go out to dinner together, unless it is a special occasion where previous arrangements have been made, it is customary, and considered proper, for everyone to pay their own way. When a male and female go on a date, it was long customary for the man to pay.
Although this social tradition has been challenged and such hard and fast rules about male versus female behavior are softening, we still often use the term “Going Dutch” when both people agree to pay for their own meal, or for whatever other expenses ensue.
“Let’s go Dutch,” we say, and by this, it is understood that both people will pay their own way. Even when groups of friends go on an outing, this phrase is sometimes used. An older version that we do not hear very often anymore is “Dutch treat.” Even less known is a “Dutch date.” What is the origin of this idiom?
The origin of “going Dutch” or a “Dutch treat” comes from a British slur towards the Dutch, and is derived from a stereotype of Dutch people as being stingy or cheap. Thus, a Dutch treat was no treat at all.
This, and undoubtedly many other examples of British animosity toward the Dutch began in the seventeenth century, when Dutch merchants were hugely important in European trade and there were disputes over lucrative sea routes between the two countries.
Holland, especially, with the important trade city of Amsterdam, was an economic and maritime powerhouse. However, since this power was not based on land or military might, was quite new, and the Dutch Republic was divided both socially and politically, the British had no reason not to challenge their commercial might.
Thus began a series of three wars, beginning in 1652, called the Anglo-Dutch wars. These conflicts, which ended in 1674, were based primarily on commercial jealousy.
During this period in England, there was a lot of anti-Dutch propaganda. Some of the speech against the Dutch, published in pamphlets, poems, and books, were quite vile, making the insult of the Dutch treat seem mild by comparison. One poem referred to Holland as the “indigested vomit of the sea” while a pamphlet claimed the Dutch were “First Bread and Descended from a Horse-Turd.”
Besides the still used going Dutch expression, from this period we also get Dutch widow, Dutch uncle, Dutch auction, and Dutch courage. The terms bumpkin and nitwit also derive from this conflict. 1Hitchings, Henry. The Secret Life of Words: How English Became English. New York: Farrar, Straus and Giroux, 2008.

Since the Anglo-Dutch wars ended so long ago, most of us never really knew of any sort of animosity between the British and the Dutch. We say “let’s go Dutch,” simply because it is a shorthand and, unfortunately, traditional way of expressing the intention that all parties will pay their own way.
We mean it quite innocently and most of us probably never really gave it much thought, let alone thought it might be a negative and insulting expression.