Historical cap from pioneer days, worn to keep hair clean and tidy. Called a mob cap, it's a white circular hat with lace trim and elastic to fit children and adults. It's a type of bonnet that was usually made of linen and worn by married women in the Georgian period when it was called a bonnet. It became highly fashionable for simple country clothing in the later 18th century.
But why is it called a 'mob cap'? During the French revolution the name 'mob cap' caught on because the poorer women who were involved in the riots wore them. Later in the Victorian period, mob caps remained popular for servants and nurses.
Today, modern versions are still worn by the pharmaceutical industry in clean rooms or anywhere hair must be contained and are usually disposable.