No, that wasn't the start of it, either.
The the black nuclear family was first legally destroyed by slavery. Slave laws explicitly denied the legal existence of marriage of enslaved persons. While freed black people re-initiated marriage and nuclear families, Jim Crow continued the war on the black nuclear family by suppressing both the ability of black men to fulfil their roles as protectors and providers and black women as wives and mothers.
It was only after the passage of the Civil Rights Act that specific laws and policies, at least, were removed as impediments to the black family.
However, by that time other social issues impacted all American families, such as no-fault divorce, birth control, and radical feminism. The black family was the "canary in the coalmine" in this situation, succumbing first to the new toxic anti-family American environment.
