AVE6326334: United States, 1960s: The tactical formations by a police unit in disruption destructive mob behavior are introduced / Bridgeman Images

AVE6326346: United States, 1960s: Men and women try to push back against police officers who use their batons to push them back / Bridgeman Images

AVE6326370: United States, 1960s: As police officers place tear gas grenades on the floor, sit down protesters get up and disperse / Bridgeman Images

AVE6326385: United States, 1960s: Protesters disperse as their eyes become irritated from the tear gas in their environment / Bridgeman Images

AVE6326433: United States, 1960s: city view at night / Bridgeman Images

AVE6326436: United States, 1960s: lady puts letters in envelopes / Bridgeman Images

AVE6326439: 1970s: An stylized cartoon post office / Bridgeman Images

AVE6326466: United States, 1960s: lady moves tins along till conveyor / Bridgeman Images

AVE6326493: United States, 1960s: machines in office / Bridgeman Images

AVE6325925: United States, 1940s: Crowd of older baseball players argue / Bridgeman Images

AVE6326066: United States, 1950s: Pan of cyclotron / Bridgeman Images

AVE6326078: Man Walks Across Garden with Lady / Bridgeman Images

AVE6326081: United States, 1950s: Panning shots of planes taking off runway / Bridgeman Images

AVE6326103: United States, 1950s: Men at control panels / Bridgeman Images

AVE6326118: United States, 1950s: Man changes piece on equipment panel / Bridgeman Images

AVE6326143: 1980s: Bi-plane taxis down runway and takes off / Bridgeman Images

AVE6326169: 1980s: Three men watch tv monitor where airplane dives / Bridgeman Images

AVE6326184: 1980s: Jet flies through air attached to plane above it, then drops / Bridgeman Images

AVE6326196: 1980s: Man climbs into cockpit of X-15 / Bridgeman Images

AVE6326207: 1970s: Man in lab / Bridgeman Images

AVE6326520: 1970s: Box with "River beauty" written on side / Bridgeman Images

AVE6326523: United States, 1960s: boat in waves on water / Bridgeman Images

AVE6326529: United States, 1960s: hand turns metal hatch on door / Bridgeman Images

AVE6326774: United States, 1960s: An artist paints a sun inside a drawing of an oven. / Bridgeman Images

AVE6326777: United States, 1960s: Two sheets are rolled through a machine to create a printing plate for a newspaper. / Bridgeman Images

AVE6326780: United States, 1960s: One man brings a metal plate to another man who uses it to do a final printing on paper. / Bridgeman Images

AVE6326798: United States, 1960s: Newsprint is fed through the rollers to print newspaper pages. / Bridgeman Images

AVE6326835: 1930s: UNITED STATES: man tests yield of purebreed cows. / Bridgeman Images

AVE6322207: USA, 1950s: Man using a ruler to draw a line on a graph / Bridgeman Images

AVE6322213: USA, 1950s: Cows grazing in field under trees / Bridgeman Images

AVE6322216: 1980s: View from a plane flying in a loop / Bridgeman Images

AVE6322249: United States, 1940s: Farm Buildings Fall Down Due to Lack of Money / Bridgeman Images

AVE6322255: United States, 1940s: Pigs on a Farm / Bridgeman Images

AVE6322258: United States, 1940s: Hay Bales in a Field / Bridgeman Images

AVE6322261: United States, 1940s: Ladies Picking Beans in a Field / Bridgeman Images

AVE6322264: United States, 1940s: Milk Production Line in a Factory / Bridgeman Images