To learn more about 19th-century America, Stacker compiled a collection of 50 essential images that capture what life was like in the 1800s.
Stacker found 50 historical photographs in archives and news sources to illustrate life in Europe before World War I.
To look at America during the Roaring Twenties, Stacker compiled a list of discoveries, trends, and changes that shaped lives in the 1920s, from news sites, historic research, scientific studies, and government reports.
Stacker searched Getty Archives to find 30 iconic World War II posters from the United States, Great Britain, the Soviet Union, Germany, Japan, Italy, and Vichy France.
Stacker has compiled winning images from the International Photography Awards (IPA) that “salute the achievements of the world's finest photographers.”