AVE6327444: 1930s: Franklin D. Roosevelt is inaugurated before crowd / Bridgeman Images

AVE6327449: United States, 1950s: modern day printing press / Bridgeman Images

AVE6327451: 1940s: Tanks roll in line / Bridgeman Images

AVE6327455: 1940s: Soldiers emerge from hold / Bridgeman Images

AVE6327459: United States, 1950s: man eats food and sorts letters / Bridgeman Images

AVE6327466: 1950s: Men in suits walk into office where man in suit and tie holds paper, speaks to them as they gather / Bridgeman Images

AVE6327478: United States, 1950s: man operates printing machine / Bridgeman Images

AVE6327479: 1950s: Hands swap out documents, raise pen to paper / Bridgeman Images

AVE6327482: United States, 1950s: printed sign / Bridgeman Images

AVE6327483: United States, 1950s: man carries books along corridor / Bridgeman Images

AVE6327485: United States, 1950s: boy prints with carved potato / Bridgeman Images

AVE6327486: United States, 1950s: boy makes printed pictures on floor / Bridgeman Images

AVE6327489: United States, 1950s: fingers dab paint on stamp / Bridgeman Images

AVE6327494: United States, 1950s: wooden door / Bridgeman Images

AVE6327507: United States, 1950s: rollers on printing press / Bridgeman Images

AVE6327525: United States, 1970s: needle moves on microamperes monitor / Bridgeman Images

AVE6327534: Puerto Rico, 1960s: Windy road towards town at base of hills / Bridgeman Images

AVE6327535: United States, 1970s: miner tests rock samples / Bridgeman Images

AVE6327538: United States, 1970s: doctor listens to man's lungs / Bridgeman Images

AVE6327539: Puerto Rico, 1960s: Man in factory operates machine / Bridgeman Images

AVE6327542: United States, 1970s: doctor points at x-rays of lungs / Bridgeman Images

AVE6327553: United States, 1970s: man inspects pipes on surface level of mine / Bridgeman Images

AVE6327555: United States, 1970s: man draws on board / Bridgeman Images

AVE6327566: Puerto Rico, 1960s: Women work on sewing machines in clothing plant / Bridgeman Images

AVE6327567: United States, 1970s: miner walks into shaft / Bridgeman Images

AVE6327568: United States, 1970s: miner drills hole in rock with machine / Bridgeman Images

AVE6327576: Puerto Rico, 1960s: Sugarcane on conveyor belt fed into processing machinery / Bridgeman Images

AVE6327586: Puerto Rico, 1960s: Beach, palm trees, mountains / Bridgeman Images

AVE6327587: Puerto Rico, 1960s: Boy and girl inside a fort / Bridgeman Images

AVE6327589: Puerto Rico, 1960s: Sign on brick wall "Department of Agriculture Forest Service US Caribbean National Forest" / Bridgeman Images

AVE6327598: Puerto Rico, 1960s: School building, American flag and Puerto Rican flag flying in front / Bridgeman Images

AVE6327600: Puerto Rico, 1960s: Teacher smiles at boy and girl in classroom / Bridgeman Images

AVE6327603: United States, 1970s: hole in mine shaft ventilation pipe / Bridgeman Images

AVE6327613: United States, 1930s: Dr. von Braun, a German leader, is seen talking to his countrymen after injuring his arm. / Bridgeman Images

AVE6327621: United States, 1930s: An astronaut gets out of his ship and wanders around in space / Bridgeman Images

AVE6327645: United States, 1950s: Scientist working on satellite / Bridgeman Images