General question about soap history

I think most of us here are well versed on the differences between glycerine soap, tallow soap, and run of the mill detergent bars.

My question is, with about a 5 yr margin of error, when did bath/body bars move away from tallow saponification (tallow based) soaps and into the chemical contrivance of soaps we have today? I am guessing it was about 1920, but dont even know where to look for that factoid.

On my research, it looks like shave soap mfrs like Williams, Yardley, Old Spice stayed with the tallow saponification as their production was many times lower that bath/body bars and could maintain most, if not all of their master recipes.

I bought a big box of some really old Swan bar soap. Got a good deal on it in bulk. But since its so old it doesnt have the ingredient list, nor the weight, and these things are monster. I am guessing they are 6-8 oz each. Just kind of wondering.

I think most of us here are well versed on the differences between glycerine soap, tallow soap, and run of the mill detergent bars.

My question is, with about a 5 yr margin of error, when did bath/body bars move away from tallow saponification (tallow based) soaps and into the chemical contrivance of soaps we have today? I am guessing it was about 1920, but dont even know where to look for that factoid.

On my research, it looks like shave soap mfrs like Williams, Yardley, Old Spice stayed with the tallow saponification as their production was many times lower that bath/body bars and could maintain most, if not all of their master recipes.

I bought a big box of some really old Swan bar soap. Got a good deal on it in bulk. But since its so old it doesnt have the ingredient list, nor the weight, and these things are monster. I am guessing they are 6-8 oz each. Just kind of wondering.

I don't know but I am going to guess when triple milled became wide spread and as companies grew larger. Most of the companies are removing the natural glycerin from their soaps and selling it to the cosmetics companies for use in their products. Thus, I have to believe it's all money driven that has resulted in cheaper detergents over quality oils, selling off the glycerin, etc.