We stopped importing slaves from Africa in 1805. So unless one of those slaves born in Africa was more than 125 years old in 1930, I think your statement may be false.
The illegal slave trade existed up until the Civil War. There was a community down in Alabama I believe made up of Africans trafficked to the US just before the Civil War. Last one died about 1930.
Children of slaves, born on American plantations, were also slaves, up until the Emancipation Proclamation in 1863.
Didn’t have to have been born in Africa and imported here, or 125 years old in 1930.