Well into the 19th century, the most notable Latin American thinkers were often concerned with the relationship between the region and the nations that had colonized it. While the essay remains a pivotal genre for Latin American public intellectuals, more latterly, in the 20th and 21st centuries, the chronicle has evolved from accounts of colonial derring-do to a greater focus on social realities or lived experiences alongside of which another related form has emerged, the testimonio. Latin American public intellectuals living and working in the United States have played a key role in defining the relationship between their countries and the Americas as a whole. Like Diaz, the New York-based Valeria Luiselli and Tulane-based Yuri Herrera are concerned with the effect of displacement and with the lived experience of migration among the poor and vulnerable. They use their fiction and non-fiction forms to engage publics.