Pure Soap
When used for laundry/cleaning performs two purposes: it softens water (by binding to hard water minerals), and cleans by dissoloving soils and oils, then keeping them along with dust and so froth in suspension to be rinsed away. One could tell when the water was properly softened by the layer of suds. If there weren't any that meant much if not all the soap was tied up softening water and keeping the gunk away from one's laundry; so you had to add more to get things back into balance.
For ages housewives, laundry workers and anyone else doing the wash with pure soap was advised to add enough product to create a creamy layer of suds a certain amount of inches high. Depth of the suds level depending upon the manner of washing (hand or machine), and what one was washing (it was known quite early in commercial laundry circles that high levels of froth help cushion items in the wash cycle, thus making for more gentle action. High water levels in the rinse cycle would do the same thing there, but wer'e not on that right now.
Laundry manuals long advised housewives and commerical laundries using pure soap that it was a "waste" to use soap as both a water softener and cleaner. Instead one was to purchase various chemical water softening agents (soda ash, washing soda, borax, phosphates, etc) and or the use of mechanical water softening systems. When using soft water one needed less soap, thus had to also replinish the same during the cycle.
When P&G first introduced Tide detergent, housewives (and others one presumes) wouldn't touch the stuff because it did not create froth. Generations of women had been taught (because of using soap for laundrry), that lots of froth meant their wash was getting clean (see above). P&G went back to the drawing board and added surfactants and or other chemicals to create high levels of froth, and that was that; sales of Tide went through the roof and ever since detergents replaced soaps for laundry day.
In the United States the main type of washing machine was the top loading style which aren't too bothered by high levels of froth. Even suds 1/3 to 1/4 up the porthole window of front loaders (remember all those lines indicating maximum suds levels on domestic and commercial front loading washing machines?), so high sudsing detergents not always were a deal breaker there.
OTHO in Europe because of earlier concerns about waves of floating froth on waterways each wash day, and as front loaders became the dominant type of washing machine, Henkel and others detergent makers began to develop not only low sudsing detergents, but surfactants that were biodegradable as well. While on this side of the pond the later occured, but not for the most part the former.
The market for detergents aside from developing countries (who just are beginning to aquire the household wealth that allows women to stop doing wash by hand, and get a washer instead), is mature and declining. Several large companies have sold off their detergent brands, and really only a handful make most all the product sold all over the world.
P&G long has known how to make "low sudsing" detergent via their products sold in the UK and EU. They dipped their toes into the water with the first "HE" versions of Tide and other detergents (a disaster as it still make lots of froth and didn't rinse cleanly if you weren't careful in dosing), while still keeping production of the high sudsing versions as well. All they really did for the former was add some anti-foaming agents anyway.
However with margins the way they are, P&G along with most every other detergent maker can no longer justify producing two different types (high and low sudsing), so now like Europe and the UK you are probably going to see only one type of product. You don't see "HE" labels on detergents across the pond because by and large all are designed to work in front loaders. You may still come across detergents labled to work for "hand washing" or some such, but with twin tub production long over, and the very limited number of top loading washers there just isn't a huge market for high sudsing detergents.
