Complex sentence: Edward Christopher Williams (1871--1929) is known as the first African-American professional Librarian in the United States of America, his sudden death on 1929 ended his career when he was expected to receive the first PHD in librarianship.
Split into simpler sentences: Edward Christopher Williams (1871--1929) is the first African-American professional librarian in the United States of America. His sudden death in 1929 ended his career when he was expected to receive the first Ph.D. in librarianship.