One of the key magazines in launching the success of photojournalism in the United States is LIFE magazine. Launched in 1936, Life went on to become the most important photojournalism magazine in the world. Specially with the World War II era photographs that were published in the magazine, for example Robert Capa's who is famously credited for saying "If your pictures aren't good enough, you aren't close enough."
After Life magazine, many other photojournalistic magazines emerged in the United States.
Of course newspapers were already using photographs in their stories, but still the emphasis was in telling stories through words. With the appearance of this kind of magazines, stories began to be told with images, which sometimes convey meaning with much more power.
I believe this magazine is what you're referring to, but I probably need more information to answer your question.