It is believed that the ancient Egyptians were the first culture to come up with the idea of covering up Armpit Odor by applying combinations of citrus oils and spices – these didn’t compound the problem by turning rancid. They also discovered that shaving armpit hair helped reduce odour. (The hair provides a large surface area for bacterial growth.)
Until quite recently, perfume was the only way to deal with armpit odor. Effective products for dealing with body odor then appeared around 100 years ago, but the market really grew in the last Century when advertising convinced people that social success was impossible with body odor. The euphemistic ‘BO’ was first used in US ads for ‘Odo-ro-no’, a product for women, in their ‘always a bridesmaid, never a bride’ campaign. At the time, even that was a brave marketing innovation, because body odor had always been one of the unmentionables, very indirectly hinted at in advertisement. Since then, the industry has never looked back.