What is the population of black Americans? How many out of #1 follow a religion? Is #2 close to or less than 50%?
Atheism
83% of blacks in the US identify as Christians.  In the United States, blacks are less likely than other ethnic groups to be religiously unaffiliated, let alone identifying as atheist. African American history, slavery and the civil rights movement are all closely tied to Christianity in America.
Absence of belief in the existence of deities
Can atheism surpass Christianity in American black communities by 2021?