Legalized discrimination - where blacks were prevented , often through violence , from owning property , or loans were not granted to African - American business owners , or black homeowners could not access FHA mortgages , or blacks were excluded from unions , or the police force , or fire departments - meant that black families could not amass any meaningful wealth to bequeath to future generations . That history helps explain the wealth and income gap between black and white , and the concentrated pockets of poverty that persists in so many of today ´ s urban and rural communities .