He earned the Doctor of Philosophy from the University of Warsaw in 1922 with a thesis on "The Jewish Question in the Kingdom of Poland During the Paskiewicz Era." Historians who studied under Shatsky include Lucy Dawidowicz.
He received a traditional Jewish education and went on to study at universities in Lwów, Vienna, Berlin and Warsaw. Shatzky enlisted in Pilsudski"s Legion and fought with distinction in the First World War. He was promoted to the rank of lieutenant.
He was sent by the Polish Foreign Ministry in 1918 to report on a pogrom in Vilna.
He resigned form his post when it became clear that the government would not act to punish the perpetrators of the pogroms. Shatzky emigrated to the United States in 1923.
He served as Chief Librarian of the New York State Psychiatric Institute from 1930 to 1956. He acquired the personal library of Sigmund Freud for the collection.