Kim Janey remembers Boston’s desegregation era, when she had rocks thrown at her on the school bus. Today, she is Boston’s first black and first woman mayor. Janey is taking Marty Walsh’s place, who became President Biden’s labor secretary. The ceremonial swearing-in was a historical event. Janey will serve as acting mayor until the election in the fall. She hopes to help the city emerge from the pandemic by addressing racism and inequality in the communities and businesses.