On July 1 in …
1770 — Lexell’s Comet passes closer to the Earth than any other comet in recorded history to that time, approaching within 0.0146 astronomical units (1,357,154.79 miles).
1863 -– The Battle of Gettysburg begins in the vicinity of the Adams County, PA, town during the Civil War.
1908 — “SOS” is adopted as the international distress signal.
1933 — Aviator Wiley Post becomes the first person to fly solo around the world, traveling 15,596 miles in 7 days, 18 hours, 45 minutes.
1963 — ZIP codes (the acronym for Zone Improvement Plan) are introduced nationwide. The delivery designation program of five digits supplanted a system of numbers for major cities that the U.S. Post Office had introduced in 1943. (An additional voluntary set of figures — the five digits followed by a hyphen and four more digits — was introduced in 1983.)