Cologne Cathedral, in Cologne, Germany, completed construction in 1880. Building had started in 1248. However, work was suspended in 1473. Centuries later, construction started again. A World Heritage Site, the cathedral hosts about 20,000 visitors per day. Children could learn more about the Cologne Cathedral at the World Heritage site: http://whc.unesco.org/en/list/292.
Social Security Act was approved by Congress in 1935. Idea: Children could learn more about Social Security and how it obtains its funds. Older children can learn more at: Social Security.
Wiffle ball was patented in 1953 by David N. Mullany. He invented the ball for his son so that it would curve when it was pitched. Today wiffle ball tournaments are popular around the world. Children can learn more at: Wiffle Ball.
Michael Phelps earned his 28th Olympic Medal in 2016. He did not medal during the 2000 Summer Olympics swimming events. At the 2004 Summer Olympics he earned six gold medals and two bronze medals. At the 2008 Summer Olympics he won eight gold medals. During the 2012 Summer Olympics he earned four gold medals and two silver medals. At the 2016 Summer Olympics he won five gold medals and one silver medal.