When Vallorie O'Neil began working for the railroad as a clerk, she told Start TV that occasionally male coworkers would discourage her, saying things like, "The railroad can hire as many women as they want, you will never run my train." That didn't stop her from becoming the first female engineer for the Burlington Northern Railroad in 1977.
She later joined Metra Commuter Rail in Chicago, where she became their first female engineer and eventually the first female Senior Train Master – a supervisor position. Her decades-long career was filled with both racism and sexism and is detailed in her book The Climb Up. Her advice to overcome adversity and advance in your field: "Do not wait to be chosen. Step up, knock on the door and ask for the position."
Watch Vallorie O'Neil talk about being the boss: