- The first photographs of Mars were taken by US space probe, Mariner 4. (1965) Mariner 4 was the fourth probe in a series of ten exploratory probes that were launched — Mariner 1-10. The objective of the series was to fly by and photograph planets. The photographs Mariner 4 returned of the surface of Mars were the first deep space photographs ever taken of another planet. The Mariner 4 mission cost about $83.2 million US Dollars (USD), and the entire Mariner series cost about $554 million USD. NASA terminated communication with Mariner 4 on December 21, 1967.
- The city of Boston, Massachusetts, stopped its racially segregated school busing system. (1999) Though the Brown v. Board of Education decision made by the US Supreme Court in 1954 ended segregation in schools, Boston continued to consider race when assigning kids to schools. On this day, the Boston School Committee voted 5-2 to end that practice out of fear of a federal lawsuit for discrimination against white students. The decision occurred 25 years to the day after a federal judge ordered the Boston School system to desegregate its schools, resulting in forced busing to schools outside a student's resident area and racial consideration for student placement. Ultimately, the situation resulted in white students being denied access to particular schools. A race-neutral admissions policy was enacted the following school year.
- Hank Aaron hit home run number 500. (1968) Aaron, considered one of the greatest Major League Baseball players in history, hit at least 24 home runs per season from 1955 to 1973 and is the only player to hit more than 30 home runs per season more than 15 times. His 755 career home run record is second only to Barry Bonds, who has 762. Aaron still holds the record for career runs batted in at 2,297 and most career extra base hits at 1,477.
- MP3s were introduced. (1995) The .mp3 filename extension was chosen by a team at the Fraunhofer Institute in Germany. The first MP3 software player, Winplay3, was introduced that year in September, allowing people to listen to MP3 files on their PCs.
- The first US National Monument honoring a black man was established. (1943) The George Washington Carver National Monument was founded by US President Franklin Delano Roosevelt. It not only was the first US National Monument to honor a black man, but also the first to honor a non-president. The monument honored George Washington Carver, who was famous for his work with alternative sustainable agriculture.
- Billy the Kid was killed. (1881) Born as Henry McCarty, Billy the Kid was a famous gunman and outlaw of the American Old West. He was fatally shot by Sheriff Pat Garrett in New Mexico after he escaped from prison, where he was serving time until his sentence to death by hanging was to be carried out.
- The United States government eliminated $500, $1,000, $5,000 and $10,000 US Dollar (USD) bills from circulation. (1969) The $500 USD bill featured William McKinley; the $1,000 USD bill featured Grover Cleveland; the $5,000 USD bill featured James Madison; and the $10,000 USD bill featured Salmon P. Chase. There also was a $100,000 USD gold certificate in 1934 which featured Woodrow Wilson.
- The US government admitted "Area 51" exists. (2003) "Area 51" is a secret US military base in southern Nevada that is primarily used to develop and test experimental military weapons and aircraft. Secrets surrounding government activity in the area has lent itself to many theories involving governmental conspiracy and UFOs.
- French citizens storm Bastille and freed seven prisoners. (1789) "The Storming of the Bastille" during the French Revolution, though it only freed seven prisoners, represents the people's resistance to French authorities. The day is celebrated in France as "Fete de la Federation" — known as Bastille Day in English.
- US President Gerald R. Ford was born. (1913) Ford served as the 38th President of the United States. He was born as Leslie Lynch King Jr., but was later renamed by a stepfather who adopted him.