In 1967, Katherine Swetzer was the first woman to enter and finish the Boston Marathon. And she finished in 4:20!
The photos shows one of the race organizers, Jock Semple (i wonder if the jock strap was named after him), trying to push her off the course demanding that she give him back the numbers, and her then-boyfriend, Thomas Miller, blocking him. I read (not in this article) that for the rest of the race, her friends that were also running created a barricade around her so she could safely finish.
5 years later, women were allowed to officially enter the race.