K, so like this is gonna be a long post:
"The search for origins, is an act of speculation, an attempt to weave a fiction of origins and subgeneration. It is to render the implicit as explicit, and at times to imagine the whole from the part."
Henry Louis Gates, Jr. 1988: xxiv
It varies but I feel the question is kinda reductive. Africaneity cannot simply be quantified in a simple way because its entrenched within the social fabric of african descended communities of the United States in many subtle and not so subtle ways.
Taking a quote that speaks of double consciousness Dubois states
It is a peculiar sensation, this double-consciousness, this sense of always looking at one's self through the eyes of others, of measuring one's soul by the tape of a world that looks on in amused contempt and pity. One ever feels his two-ness,—an American, a Negro; two souls, two thoughts, two unreconciled strivings; two warring ideals in one dark body, whose dogged strength alone keeps it from being torn asunder.
The history of the American Negro is the history of this strife – this longing to attain self-conscious manhood, to merge his double self into a better and truer self. In this merging he wishes neither of the older selves to be lost. He does not wish to Africanize America, for America has too much to teach the world and Africa. He wouldn't bleach his Negro blood in a flood of white Americanism, for he knows that Negro blood has a message for the world. He simply wishes to make it possible for a man to be both a Negro and an American without being cursed and spit upon by his fellows, without having the doors of opportunity closed roughly in his face.
In Paul Gilroy's book of "The Black Atlantic: Modernity and Double Consciousness" he posits that the directionality and conditions of the not only the slave trade but the Euro-African interactions from the 15th century onwards in the pre and early colonial world shapes and shifts the way Africans seen and engaged not only amongst themselves but the the broader Atlantic Ocean littoral in the initial Charter Generation. As of the 20th century and now though
Examples: The "Gullah" are often perceived as being the most "African" population of the United States: Their dialect, food ways, cultural ways, lack of intermixture etc... But no one ever takes a moment to consider Louisiana even with its very large mixed race population retain a creole, food way, religious and cultural expression that is along similar veins of engaging and being.
We ignore the Seminole Freemen who themselves are an expansion of "Gullah", as well as other populations related to the Sea Islands and/or the American mainland of the late 18th and early 19th century: The Mericans of Trinidad and Tobago, the Macagos Americans of northern Mexico, the Samana Americans of the Dominican Republic
_____________________________________
But I'd like to ask another question: do we take time to recognize the subaltern world of American Blacks of the Mainland United States?
I do not necessarily agree in the acceptance in the narrative that "African" culture was merely destroyed. It like all processes of Creolization transmuted. Much like AAVE and its precursors that derived
before their enslavement on the West African coast.
These characteristics that seem "washed down" were in fact consolidated due to external forces creating a new iteration of identity. To religion we have the formation of "Invisible Institutions"; foundational black congregations with a rather subversive worldview and mindset of a Christianity seeking to instill a sense of this subservience to that of syncretization with the forms of worship and paradigm much aligned with say Vodou, Palo, Santeria & Candomble. In fact after the 1812 War the American Black slaves brought to Trinidad ancestors of Mericans introduced Spiritual Baptist and Shango Baptist faiths giving a lens of religious practices Blacks did amongst themselves when whites were not looking.
No one who ever wrote about this sort of topic in the past will ever fully know what life was truly like for American blacks from the pre-1900s; be they white or the sanitizing eyes of elite American blacks all too anxious to show their parity to American Whites.
We also see in the United States and the Americas the dispersal of music, foods ways and religious practices that were absorbed into non-black communities are basically being washed of its origin rendering outside of the idea of what you might say is "African".
In closing I'm saying all this to mean that your search for hard set things overshadows the way in which the vast majority of the culture of enslaved American blacks persists into the present day or at least the post-reconstruction era and the great migration, it just evolves like culture in general.
Also i'll just add that even after 300-150 years on this goddamn rock and mixing with many different groups there are still people who maintain the identity of being Malagasy so yeah that adds some context to like just how the whole "Whites mixed up all the slaves so they wouldn't have an identity" quip folks make.