I know this is a half-truth (I research probate inventories. I never see women of British heritage with underpants in their inventories. Sometimes, men do. But not often and it is one pair. )  However, as much as I really want to say, "Not everyone who immigrated to America went commando during the colonial era", it would turn into an back and forth. And in the end, I sort of think they like it this way. 

Silly topic but ... does anyone know why British people didn't ware underpants until the Regency era? My hypnosis is that it 1) they lined their breeches for men, 2) women in under breeches offended men 3) they were erroneously associated with prostitutes who wore knee length silk breeches (they have a button closure) as opposed to the linen drawstring ones I find in inventories. 

Any thoughts? 

I didn't know the Brits wore them in Roman times. I know the Romans, and later Renaissance Italians did wear them and continued to do so through to modern times. So, yeah, why did the Brits stop waring them between Roman and Regency? But especially in the 17th and 18th century when breeches were worn. 

It does seem like the Scots are the last holdouts. 

In Italy it was the Catholic nuns. But even they went with it once they realized they could just share or have communal underpants. (They took a vow of poverty, in the 16th century "only the most destitute" were without the most basic of garments... underpants. Communal underpants got around the vow of poverty.) 

No, not technically. So, drawers, underpants, and "underwear bottoms" are always worn as a first layer "under" an out-ter garment. 

So, Italian people had a briefs they wore under their one-peace tights. These were the cheapest form of underwear bottoms for them in the middle ages. They were not made as a "pair" but made from one piece of fabric. Both men and women wore them. There are other kinds, but the brief was the most common and basic.