Fred Stein arrived in New York with his wife Lilo Stein and daughter Marion on 13 June, 1941, after the family had suffered months of uncertainty and anguish. Stein and his wife had left his native Dresden for Paris in 1933 under the pretext of a honeymoon trip and, once there, autodidactically opened a photographic studio in their apartment. When France declared war on Germany in September 1939, they left the French capital. After the German invasion of France in early 1940, Fred Stein was sent to several internment camps, while his wife and daughter found refuge, first in Normandy, then in Brittany, before returning to Paris, thanks to the help of some influential friends. On a two-day departure from the internment camp to Paris, Fred Stein was able to save the Parisian apartment from foreclosure and liquidate it. Stein was held in a prison camp in Saint Nazaire for British expeditionary troops engaged in the fight against Hitler, but, along with some other inmates, managed to escape, dressed in civilian clothes, and make his way along country roads into unoccupied southern French territory. During his flight, Stein sent postcards under an assumed name to Lilo Stein in Paris, in which he spoke about an alleged meeting with a friend in Toulouse. Lilo Stein understood the cryptic message and immediately departed for the South of France. Since she spoke fluent French, she was able to pass herself off as French and travel to Toulouse without a permit. In her suitcase were some of Fred Stein's negatives and photographs. In Toulouse, the family were finally reunited, but endured several months of insecurity and fear of arrest until they were offered help by the Emergency Rescue Committee. Founded in New York in 1940, the organisation had sent the journalist Varian Fry to Marseille to manage the escape of several thousand fugitive artists and intellectuals.

On 6 May, 1941, the Stein’s were fortunate enough to leave Marseille on board the S.S. Winnipeg bound for New York in the company of several other persecuted photographers, among them the German photographers Josef Breitenbach, Ilse Bing, Yolla Nichlas-Sachs, Monnie Tannen and Fritz Neugass, as well as the Belgian photographer Charles Leirens and the Hungarian photographer Ylla (Neugass 1951). It’s not known if the photographers knew about each other's presence on board. Interestingly, Ilse Bing, Yolla Niclas and Josef Breitenbach took photos on board the S.S. Winnipeg. Unfortunately, the passage involved a number of detours. Suspecting it to be enemy ship of the National Socialists, the Dutch Navy stopped it and all passengers had to be transferred to British internment camps in Trinidad. On 6 June, 1941, the Stern family could finally left Trinidad on board the S.S. Evangeline and arrived on 13 June, 1941. Yolla Niclas-Sachs and Rudolf Sachs took the same ship. Similar detours on the passage had to be experienced by the photographer Lilly Joss, who instead of a crossing to Great Britain had to make a forced stay in Casablanca and in November 1941 reached New York.

Stein was able to take some of his negatives and photographs with him, but not his camera. However, Lilo Steins's mother, who was already living in California, helped finance the purchase of a new Leica. Restarting life again was not easy for the family. During his early days in New York, Fred Stein spent most of his time trying to sell his photographs of Paris and writing to such organisations as the Amateur Cinema Club, as well as the United Sates government and Varian Fry, in search of addresses and ideas for selling his images. Through his correspondence it is know that he remained in contact with his Paris colleagues and friends, including Ylla, Josef Breitenbach, and Hermann Landshoff, and worked hard to expand his cultural and artistic émigré and American network.
Stein landed his first big project in 1945 with a calendar for the American Relief for France organisation, featuring photographs of Paris by him. This calendar project was continued in 1948 and 1949, with images of New York by him (Lumen Publisher). From 1942, Stein was able to sell some of his photographs through the Rapho Guillmette photo agency, which he was familiar with from his time in Paris, and started selling his work to and receiving commissions from the PIX photo agency from 1943. He worked as a freelance photographer with the Black Star Agency from October 1943 until the 1950s, which was found by the German émigrés Kurt Safranski, Kurt Kornfeld and Ernest Mayer. The agency, which charged a 50% commission fee, allowed him to sell his photographs to a wide range of international magazines, newspapers and books, including U.S. Camera, Minicam Magazine, Time, Colliers, The New York Times, La Victoire, Vogue, Voici, Jews for France, Life, Lilliput, Photography and Popular Photography. Stein's commitment to selling his photographs to as wide a range of publications as possible is reflected in the way he stored them – he called them reportages and ordered them alphabetically according to topic. Other émigré photographers who worked for Black Star were for example Ruth Bernhard, Andreas Feininger, Lilly Joss, Fritz Henle, Carola Gregor (and his husband Fritz Goro), Werner Wolff, Walter Sanders.

Fascinated by the city, Stein worked most of the time on his own, exploring the streets of the metropolis and capturing the sights he saw in his own personal style. His interest in the human side of city life, with its humorous everyday scenes and many different social categories of citizen are captured in his first US photobook project, 5th Avenue (Pantheon, 1947). Like Fritz Henle, Andreas Feininger, Ellen Auerbach or Rudy Burckhardt as well as other émigrés photographers encountering the city, he walked the city from south to north. For Stein, his camera was an instrument for getting acquainted with the city and artistically capturing in photographs the images and views he encountered. The photobook, which he sent to a number of well-known magazines, organisations and colleagues, was reviewed and written about in a number of articles. The New World Club organised an author’s evening and “Mit der Kamera von der Seine zum Hudson” and Aufbau magazine published an article about him and his new book (Craener 1947). Lilo Stein collected all the reviews and articles in two scrapbooks. We learn from these that he had two minor exhibitions towards the end of the 1940s. One was Art of the Portrait, together with the cartoonist Dolbin, at the Tribune Subway Art Gallery in 1946; another was the Children Photographs exhibition at the Gallery of the Parent’s Magazine (52 Vanderbilt Avenue) in June 1947.

Stein's sensitive and humane approach and his habit of treating everyone as equals can be seen in his series of portraits of emigrants, intellectuals, artists and politicians. During his lifetime he made more than 1500 of these portraits, spanning a wide range of subjects that included Albert Einstein, Fritz Landshoff (of the Querido Verlag), Hannah Arendt, Eleanor Roosevelt, Marc Chagall, Max Ernst, Anette Kolb, Arnold Schönberg, Leonhard Frank and Alvin Johnson (president of the New School for Social Research). Many of these appeared in Aufbau magazine. In the archive of Fred Stein there are references via business cards and letterheads suggesting that Stein made a couple of attempts to open his own studio as an “illustrative photographer” in the best areas of Manhattan (38 East 65th Street / 119 West 57th Street). The dates and exactly how long these existed are not known, but with the income they generated insufficient to cover the rent, they did not last long.
Especially after he had to abandon his street photography at the beginning of the 1960s because of hip problems and surgery, portraiture became his principal photographic medium. His ability to gain the trust of his subjects is evident from the close-up shots he took. By the end of his life Stein had produced portraits of most prominent artists, writers, politicians and thinkers of the time, as well as of other individuals who captured his interest. Fred Stein's photographic career is well documented in part through scrapbooks and correspondence, thanks mainly to his wife Lilo Stein, and today in the hands of his son Peter Stein. It is thanks to his efforts that, today, after years of oblivion, his father's work is preserved and on display in international museums.