Scholars have typically assumed that the invariant am typical of minstrel depictions of black speech was a fabrication, used neither by modern nor earlier black Americans. However, the frequency with which invariant am occurs in transcriptions of ex-slave speech has always lent a certain uncertainty here, despite claims that these must have been distortions introduced by the transcribers. I argue that the use of invariant am in a great many literary sources written by black writers with sober intention, as well as grammatical descriptions of black speech which note invariant am as a feature, suggest that invariant am was a now extinct form in earlier Black English, largely eclipsed by World War II but common among black slaves and their immediate descendants.