After learning his long-ago relative, Julius Caesar Tingman, joined the Union Army after 21 years in forced servitude and later went on to become a politician, Rock said the unearthed news was a lot to comprehend, the New York Post reported Sunday.
"I'm going to cry. I can't believe this. I never knew any of this," the comedian said.
The news was presented to Rock as part of the PBS series "African American Lives 2," which allows black celebrities to learn unknown facts about their ancestors.
Rock said if he had known his family's history in more detail earlier in his life, comedy would likely not have been his chosen field.
"I mean it's weird, if I'd have known this, there's a good chance I wouldn't be a comedian," Rock said.