May 5, 1818 – Karl Marx, author of the Communist Manifesto, is born in Trier, Germany.
May 6, 1856 – Psychoanalysis founder Sigmund Freund is born in what is now Pfibor, Czech Republic (which originally was part of the Austrian Empire).
May 6, 1856 – American Arctic explorer Rear Admiral Robert E. Peary is born in Cresson, Pennsylvania.
May 11, 1888 – Prolific popular song writer Irving Berlin is born in Tolochin, Russia.