AVE6327472: United States, 1950s: man polishes machine / Bridgeman Images

AVE6327517: United States, 1950s: animation of printing press machine / Bridgeman Images

AVE6327399: United States, 1950s: Wipers clearing rain from windscreen of car / Bridgeman Images

AVE6327423: 1950s: Painting of men, women on horseback and foot with guns / Bridgeman Images

AVE6327432: United States, 1950s: hand folds newspaper / Bridgeman Images

AVE6327389: United States, 1950s: View through windshield as car drives down steep hill / Bridgeman Images

AVE6327447: United States, 1950s: fonts for printing press / Bridgeman Images

AVE6327416: 1950s: Actor playing George Washington looks out, bows at inauguration, puts hand on heart, hand on man's Bible, surrounded by Founding Fathers / Bridgeman Images

AVE6327471: 1950s: People exit stairway of building / Bridgeman Images

AVE6327425: 1950s: Reenactment of Abraham Lincoln with raised hand, swearing in / Bridgeman Images

AVE6327480: United States, 1950s: newspaper on printing press machine / Bridgeman Images

AVE6327461: 1950s: Chair of president's desk in Oval Office / Bridgeman Images

AVE6327501: United States, 1950s: man carves individual letters for printing / Bridgeman Images

AVE6327506: United States, 1950s: flames in iron mongers workshop / Bridgeman Images

AVE6327504: United States, 1950s: boys working in printing press with machines / Bridgeman Images

AVE6327527: United States, 1970s: animation of thorium 234 molecule / Bridgeman Images

AVE6327552: Puerto Rico, 1960s: Man loads oxen-led cart with sugarcane / Bridgeman Images

AVE6327572: United States, 1970s: man in science lab / Bridgeman Images

AVE6327585: United States, 1970s: men repair hole in ventilation pipe inside mine shaft / Bridgeman Images

AVE6327590: Puerto Rico, 1960s: Flowers in rainforest / Bridgeman Images

AVE6327617: United States, 1930s: A dog prepares to go to space with different tests / Bridgeman Images

AVE6327636: Germany, 1940s: A rocket successfully launches and opens fire in a town / Bridgeman Images

AVE6327632: Germany, 1940s: Scientists build a rocket and weapons / Bridgeman Images

AVE6328132: Europe, 1940s: people walk to funeral in black clothes / Bridgeman Images

AVE6328147: Europe, 1940s: hand fills container with water / Bridgeman Images

AVE6328150: United States, 1960s: man writes E=MC2 on blackboard / Bridgeman Images

AVE6328165: Europe, 1940s: baby cries in crib / Bridgeman Images

AVE6328195: Europe, 1940s: men and women eat food in building rubble / Bridgeman Images

AVE6328198: UNITED STATES: 1981: People looking up at sky as space shuttle takes off. / Bridgeman Images

AVE6328201: Europe, 1940s: people walk through streets / Bridgeman Images

AVE6328207: Europe, 1940s: supplies piled high in dock warehouse / Bridgeman Images

AVE6328225: UNITED STATES: 1981: Seated astronaut working inside cabin of space shuttle. / Bridgeman Images

AVE6328255: UNITED STATES: 1981: Space shuttle closes doors. / Bridgeman Images

AVE6328258: UNITED STATES: 1981: Computer grid showing location of space shuttle in relation to countries on Earth / Bridgeman Images

AVE6328291: UNITED STATES: 1981: Space shuttle slows down on runway as it lands. / Bridgeman Images

AVE6328300: UNITED STATES: 1981: Close up of front of space shuttle as it lands on sandy runway. / Bridgeman Images