In 1966, Roberta "Bobbi" Gibb became the first woman to complete the Boston Marathon, though she ran as an unregistered racer. The following year, Kathrine Switzer registered under the name K.V. Switzer and ran the race with an official bib, though she had to be protected from race officials who tried to physically assault her in order to remove her from the race.
This incident, in which marathon official Jock Semple appears to be attacking Switzer, is documented in black-and-white photographs. Switzer's boyfriend and other male racers are seen defending Switzer in these photographs, which were taken during the race's second mile. Due to this incident, and the fact that she was a registered racer, Switzer's entrance in the race is a bit more well known than Gibb's, though Gibb was before Switzer as well as faster.
At the time, the Boston Athletic Association, the group responsible for hosting the Boston Marathon, officially banned women from entering the race. Many people believed that women were too delicate to participate in extreme physical activities, such as a marathon. This idea has been proven wrong time and again by elite female athletes like Gibb and Switzer.