For Women’s History Month, Atlas Obscura delves into the world of espionage, where being overlooked and underestimated has been an asset for centuries of women spies. Read about more of history’s hidden Secret Agent Women. Pedro Herrera awoke each morning before dawn in a military camp in northern Mexico to dress and shave a beard that was “just starting to grow out,” as Herrera reportedly told the other soldiers. The 20-something was a respected figure in the revolutionary unit, a natural leader with a skill for blowing up bridges and…