Modern Bra
Mary Phelps Jacob's Brassiere wasn't the first bra-like design to be patented, but timing and fashion helped it become the springboard to modern bra designs and features.
In 1910, 19-year-old New York socialite Mary Phelps Jacob was getting dressed for a debutante ball but found every corset she tried showed through her gown. With her maid's help, she sewed two silk handkerchiefs and a ribbon into something soft enough to disappear under the dress.
She patented the design simply as "Brassiere" in November 1914. It wasn't the first bra-like patent on record. Marie Tucek had already patented the "breast supporter" - a garment with separate breast pockets and shoulder straps back in 1893 - but Jacob's is the one credited with kicking off the modern era, mostly because World War I arrived soon after and metal-boned corsets quietly disappeared from wardrobes.
She later sold the patent to the Warner Brothers Corset Company for $1,500, who manufactured her exact design for a while before discontinuing it. The $15 million Warner eventually earned came from what they built on top of the patent: elastic, adjustable straps, cup sizing - features that are common today, but missing from Jacob's original design.
Mary Phelps Jacob's patented design is not the bra that made Warner millions, but it is the one that led us to modern bra design.