The photograph could be of anything important in history. From World War II to Martin Luther King Jr’s speech. It impacts Americans because it lets them realize and learn about our history through a different perspective. Hope this helps! :)
It was on the 19th and the 20th century when Photojournalism came out and became popular in the US and Europe. The photographs captured were mostly from the war. Some captured interesting stories about culture. The largest magazines come from Europe called Münchner Illustrierte Presse and the Berliner Illustrirte Zeitung. While in America it was known as Life and Look.