gone in a flush: the first disposable pads
The first disposable pads available for sale in America were Listers Towels by Johnson & Johnson introduced in 1896. These pads were made from gauze-covered cotton and could be ordered privately through the mail. Because menstruation was more or less an unspoken subject during this time, disposable pads were rarely advertised and didn't sell very well.
America saw the first widely successful disposable pads in 1920: Curads by Kotex. Curads started as cotton bandages for soldiers in World War I until nurses who tended to the soldiers noticed that the bandages could double as disposable pads.
Curads didn't take off right away, though. Lots of women were embarrassed to buy pads in public, so stores allowed women to place their money in a box and walk out with their Curads discreetly. Modess dealt with women's embarrassment by publishing "silent purchase coupons" in magazine ads, so women could hand the cashier a slip of paper instead of verbally asking for pads. If anything, these efforts only made the idea of menstruating seem more shameful.