In pictures: UPI's most iconic pictures of the 20th century (50 images)

There are more than 3 billion cameras in use across the world, but over the course of the 20th century, as the medium was coming into its own, the documenting of world events rest in the hands of a few. One of those trusted organizations was UPI Newspictures. Formed in 1952 with the absorption of Scripps' ACME Newspictures, and then expanded on May 24, 1958, when United Press merged with Hearst's International News Service, UPI Newspictures produced many of the most important images of the century and continues to do so to this day.

An American soldier with the First Army Division sleeps atop a pillbox bunker during a monsoon downpour following heavy Vietcong sniper and mortar fire near Phuc Vihn, South Vietnam on June 17, 1967. Winner of the 1968 Pulitzer Prize for Feature Photography. Photo by Toshio Sakai/UPI

Music legend Louis Armstrong entertains his wife, Lillian, in front of the Sphinx during a trip to Egypt in 1961. UPI File Photo

The largest manmade object ever to fly, the 800-foot airship Hindenburg erupts in a fireball at Lakehurst, N.J., on its arrival from Europe on May 6, 1937. Static electricity ignited the airship's flammable fabric skin, and 37 seconds later the airship crashed to the ground, killing 35 of its 97 passengers and crew. This spectacle ended the era of the passenger airship. Photo by Sam Shere/INS/UPI

Unemployed bread lines; despite a heavy rain, these poor unfortunates, jobless and moneyless, wait in line at Grand and Christie streets in NYC for nourishment being doled out ca. 1930. Photo by ACME/UPI