 In 1967 he was commissioned to shoot a portrait of former Black Panther H. Rap Brown.Noticing the trend of a call for civil rights in the late 1960s, Boston took more images of the Civil Rights Movement, including a portrait of Reverend Martin Luther King, Jr. during his Poor People's Campaign, and other notable events.On October 22, 1967 he photographed his most famous picture, "Flower Power", which showed a Vietnam War protester inserting flowers into National Guardsmen's rifle barrels.