Switzer ran Boston Marathon as registered bib #261 'K.V. Switzer,' becoming the first official female entrant, despite race director Jock Semple's attempt to forcibly remove her.
On April 19, 1967, Kathrine Switzer made history by becoming the first woman to officially register for and run the Boston Marathon as a numbered entrant. Registering under the gender-neutral name "K. V. Switzer," she was issued bib number 261 by race officials who did not realize she was a woman, since at the time the rules of the Amateur Athletic Union explicitly barred women from running distances longer than 1.5 miles.
Several miles into the race, official Jock Semple noticed Switzer and attempted to physically pull her from the course, shouting for her to give him her race numbers. Switzer's boyfriend, Tom Miller, a former All-American football player, shoved Semple aside, allowing her to continue. A press photographer captured the altercation, and the resulting images were published around the world, becoming an iconic symbol of women's fight for equality in sports.
Switzer finished the race in approximately 4 hours and 20 minutes. Her run was distinct from Roberta "Bobbi" Gibb's unregistered participation the previous year (1966), because Switzer was the first woman to run with an official bib number as a registered entrant, directly challenging the rules that excluded women.
This event is widely credited with catalyzing the movement to officially open marathon running to women, leading eventually to the inclusion of a women's division at Boston in 1972 and the women's Olympic marathon in 1984.