Caleb Barr Jr was 9 years old when The Holocaust: The first prisoners arrive at a new concentration camp at Auschwitz. The Holocaust, also referred to as the Shoah, was a genocide during World War II in which Nazi Germany, aided by its collaborators, systematically murdered some six million European Jews, around two-thirds of the Jewish population of Europe, between 1941 and 1945. Jews were targeted for extermination as part of a larger event involving the persecution and murder of other groups, including in particular the Roma and "incurably sick", as well as ethnic Poles and other Slavs, Soviet citizens, Soviet prisoners of war, political opponents, gay men and Jehovah's Witnesses, resulting in up to 17 million deaths overall.
Caleb Barr Jr was 22 years old when Jonas Salk announced the successful test of his polio vaccine on a small group of adults and children (vaccination pictured). Jonas Edward Salk was an American medical researcher and virologist. He discovered and developed one of the first successful polio vaccines. Born in New York City, he attended New York University School of Medicine, later choosing to do medical research instead of becoming a practicing physician. In 1939, after earning his medical degree, Salk began an internship as a physician scientist at Mount Sinai Hospital. Two years later he was granted a fellowship at the University of Michigan, where he would study flu viruses with his mentor Thomas Francis, Jr.
Caleb Barr Jr was 33 years old when Martin Luther King Jr. received the Nobel Peace Prize for combating racial inequality through nonviolence. Martin Luther King Jr. was an American Baptist minister and activist who became the most visible spokesperson and leader in the civil rights movement from 1954 until his death in 1968. Born in Atlanta, King is best known for advancing civil rights through nonviolence and civil disobedience, tactics his Christian beliefs and the nonviolent activism of Mahatma Gandhi helped inspire.
Caleb Barr Jr was 41 years old when Munich massacre: Nine Israeli athletes die (along with a German policeman) at the hands of the Palestinian "Black September" terrorist group after being taken hostage at the Munich Olympic Games. Two other Israeli athletes were slain in the initial attack the previous day. The Munich massacre was an attack during the 1972 Summer Olympics in Munich, West Germany, in which the Palestinian terrorist group Black September took eleven Israeli Olympic team members hostage and killed them along with a West German police officer.