Sunday marked one year since the racist mass shooting in Buffalo. Melissa Harris-Perry sits down with Buffalo Mayor Byron Brown to reflect on the tragedy and discuss how the city is coping right now. The tragic shooting is one of several disturbing massacres motivated by hate that have occurred in recent years. But the history of race based violence dates back to the beginning of what is now the United States, and some of the recent racially motivated attacks call to mind some of the racist violence that targeted Black communities in the early 20th century. We also speak with journalist and professor Jelani Cobb about this history.