Thousands of American women have courageously spoken in public over the past four centuries. Their speeches helped shape the beliefs, culture and ideals of America. But their voices have been omitted from American history, and our storehouse of common knowledge. The same cannot be said about the many lionized male orators who appear in our history books, media, and public discourse.

I know because when I give talks and teach classes in public speaking, I ask my audience: “Which famous speakers in American history can you name?” Many people can rattle off at least half a dozen American male speakers like Abraham Lincoln, Franklin D. Roosevelt, Martin Luther King, Jr., John F. Kennedy, Robert F. Kennedy, Billy Graham and Ronald Reagan. But when I ask which women speakers they remember, there’s a long pause. Someone might mention Hillary Clinton or Michelle Obama. Mostly the faces are blank.

Could it be true, I wondered, that the “great men” in history gave all the greatest speeches? Or could it be we just don’t know about great women speakers?