I have a middy blouse from the teens or 20s with this label and did a search only to find that the company was in business until at least the mid 1960s (judging by the merch with this label on eBay and Etsy) and the label never changed. They seem to have started off with sportswear - midis, gym strips etc. then by the 1940s branched into cotton housedresses and finally into little cotton shifts by the 60s. I found adverts for their cotton dresses in two newspapers 1950 and 1954, but nothing else. No date of origin, obit attributed to the owner/founder, no location of factory, or when it went out of business...
Well, I haven't found any adverts older than the 50's. I found 12 adverts but those wouldn't help in regards to the earlier info your looking for. I did find one BillSims Togs bathing suit that was listed as being from the 20s/30s that was listed on Polyvore as being sold previously on Etsy. http://www.polyvore.com/vintage_1920s_30s_blue_sleeveless/thing?id=129564428&m=upsell
I am a little late to weigh in on this but.....I am closing out my mother's estate and they saved everything. I have boxes of dresses, lingerie, corsets, hats, gloves, lace, purses, on and on. I found two middy tops (identical) with the label Bill Sims Togs. The blouses are light brown maybe with pink tones. I would have guessed from around 1940. My mother attended a college at that time in Northern Ohio whose colors were brown and gold. When I googled Bill Sims Togs this post popped up. Are there any organizations in the USA that are interested in vintage clothing? I would be glad to donate them to a happy home. I am in Atlanta, GA
The earliest ad I found was from 1920: This 1921 ad suggests that the brand was named for an actual figure, a popular WWI era admiral (a 1918 article about Sims follows the ad): From 1923: 1929:
Good question, Suzanne! Turns out there's a Canadian connection--(acc to Wikipedia) William Sims was born in Port Hope, Ontario. Other interesting facts--he won the 1921 Pulitzer prize in history for his book about his WWI experiences, and was on the October 26, 1925 cover of Time--so a very popular figure while those middies were being sold.
So the label was named after THIS guy: https://www.britannica.com/biography/William-Sowden-Sims And although he was an American admiral, he was born in Canada!
Amazing . Carrie wins the detective award award. It is inter sting how one man influenced a whole fashion trend and label and not much is known of him today. Will you be doing an exhibit Jonathan?