Construction of the dome of Santa Maria del Fiore began in Florence on August 7, 1420.
The Battle of Guadalcanal began on this day in 1942 as United States Marines initiated the first American offensive of the Second World War with landings in the Solomon Islands.
On this day in 1947, Thor Heyerdahl's balsa wood raft the Kon-Tiki smashed into a reef in the Tuamotu Islands after a 101-day, 7,000-kilometer journey across the Pacific Ocean in an attempt to prove that prehistoric peoples could have traveled from South America. The crew of six made successful landfall and all returned safely.
On this day in 1987, Lynne Cox became the first person to swim from the United States to the Soviet Union, crossing from Little Diomede Island in Alaska to Big Diomede in the Soviet Union.