In the "who knew?" category comes this 1946 exchange between B.R. Ambedkar, the preeminent leader of India's Dalits, and W.E.B. DuBois, the noted African-American sociologist and activist. From the South Asian American Digital Archive:
An interesting record appears in the papers of W.E.B. Du Bois, the prominent African American intellectual and activist, whose archive is housed at the University of Massachusetts. In the 1940s, Ambedkar contacted Du Bois to inquire about the National Negro Congress petition to the U.N., which attempted to secure minority rights through the U.N. council. In a letter dated July 31, 1946, Du Bois responded by telling Ambedkar he was familiar with his name, and that he had "every sympathy with the Untouchables of India."
To read the letters, visit the South Asian American Digital Archive.