From the pacification of favela communities in Rio de Janeiro to the heavily militarized police presence in Ferguson, Black citizens in Brazil and the United States must constantly assert why our lives matter. In what way does the common struggle for our humanity work to create community and solidarity among Black-identified individuals of diverse national origins? What happens when Black people encounter the suffering of other Black populations? In what ways does Black solidarity abroad open the possibility of an international Movement for Black Lives? Through a comparative analysis of the state of Black citizenship in Brazil and the United States, based on fieldwork observations, autoethnographic reflections, and interviews, I argue that the transnational vertigo of violence can connect local Black experiences with patterns seen across the diaspora, inspire sentiments of solidarity among disparate communities, and serve as a basis for a worldwide Movement for Black Lives.