Martin Luther King Jr.
As a person, Martin Luther King Jr. looms large over the 1619 Project. As most know, King was a Civil Rights icon responsible not only for giving groundbreaking and breathtaking speeches like "I Have a Dream," but for giving validity - and more importantly, a voice - to the Civil Rights movement - a movement which resulted in the Civil Rights Act of 1964.
Without King, black Americans would perhaps not have the same rights that they do today. He is undoubtedly one of the most important figures in history.
Lucas Vázquez de Ayllón
Ayllón was responsible for the establishment of the colony San Miguel de Gualdape (on the Georgia or Carolina coast) in 1526, which was one of the first colonies created by Europeans of the New World. San Miguel de Gualdape was also the first colony to have slaves in the New World (slaves who would later kill many of their slavers and the colony itself a few months later). In that sense, Ayllón was the man most directly responsible for the creation of the African slave trade in the New World.