Rostow was born in Manhattan, New York City, to a Russian Jewish immigrant family. His parents, Lillian (Helman) and Victor Rostow, were active socialists, and named Walt after the poet Walt Whitman. Rostow's father, Victor Rostowsky, was born in the town of Orekhov near Odessa in 1886, and was involved in the Russian socialist movement as a teenager, publishing a left-wing newspaper calling for the overthrow of the Emperor Nicholas II in the basement of his parents' house. In 1904, at the age of 18, Victor Rostowsky boarded a ship that took him from Odessa to Glasgow and another ship that took him to New York. Upon arriving in the United States, Rostowsky "Americanized" his surname to Rostow. On 22 October 1912, he married Lillian Helman, the intellectually gifted daughter of Russian Jewish immigrants who longed go to college, but as her family was too poor to afford higher education, she instead encouraged her sons to attain the higher education she wanted for herself. Like the Rostowskys, the Helmans were "Ashkenazim" (Yiddish-speaking Jews). The Rostows were described as being very "idealistic" immigrants who deeply loved their adopted country and named their three sons after the three men they considered to be the greatest Americans, namely Eugene V. Debs, Walt Whitman and Ralph Waldo Emerson.