A New York Socialite named Mary Phelps Jacob created the first modern brassiere in 1913. It was made out of two silk hankerchiefs and some pink ribbon, and was a savior after those corsets that were usually worn. The corsets were made out of steel rods and whaleback bones, and were not only uncomfortable, but protruded from women's clothing at times.
So, Jacob created the bra, and received a patent for this "Backless Brassiere" on November 3, 1914. She sold many copies under her production name, Caresse Crosby, but she soon became bored. She chose to sell the patent for $1,500 to the Warner Brothers Corset Company in Bridgeport, Connecticut. However, Warner Brothers Corset Company made $15 million off the brassiere in the following 30 years.
Jacob died in 1970 after her brassiere had undergone many transitional changes. She is on my list because of this question: would the world be the same without the modern day bra? Of course not!