You never know from where inspiration will come.

I am often envious of my friends who can recite stories about ancestors that have been handed down through generations. I can't do that. As a descendant of slavery in America, that hasn't felt possible for me. Truthfully, I didn't think about it much until a few weeks ago, after I was asked by CNN's In America team to write about the impact of a mixed racial background on my life, the idea that "one drop" of black blood makes you black.

In that article, I wrote about how my aunt and grandmother in Louisiana often were mistaken for white. I wrote about the extremes they went to in order to protect their husbands, who were black, from beatings by white men, or worse.

As I began to write the article, I sent a text message to my mother asking that she email photos of my aunt and grandmother. She sent me what she had, but asked why I wanted them. I told her I'd call to explain once I got home that evening.

When I finished the draft of the article, I zipped off a copy to her via email. A few minutes later, as I was driving home from work, my phone rang. When my mother began to tell me the stories of my aunt and grandmother, I had to pull over in a parking lot to take it all in. Some of it I knew. Much of it I didn't.

My mother said, "Don, your aunt and grandmother really are quintessential 'one drop' Americans."

"Why, mom?" I asked.

"I know you overheard some of this as a child, but your aunt's father was a white man," she said. "Your grandmother's father was a white man."

"Yes," I said, "I remember now."

My aunt, my grandmother's eldest daughter and the one often mistaken for white, was the product of rape, my mother told me. My grandmother worked for a white family in a small Louisiana town in the 1920s. According to my mom and other family members, the man of the house raped my grandmother. She was barely a teenager at the time.

When her grandfather found out about the rape, my mother said, he picked up a shotgun intending to kill the man. But his siblings held him down long enough for his anger to subside, long enough to talk him out of it. A good thing, according to my mother - the man who raped my grandmother was also the town sheriff.

It wasn't the first time it had happened in my family. My grandmother's father also was white. Her mother died during childbirth, and in 1919 Louisiana, it was all but impossible for a white man to raise a black child. So, her grandparents took her in.

Confused? I am too.

But that's what inspired me: I want to trace my ancestry. I've reached out to an expert, Henry Louis Gates Jr., to guide me through it.

Wish me luck.

The opinions expressed in this column are solely those of Don Lemon.