- Jul 1 Mammoth Cave National Park established with 45,310 acres, including world's largest cave network in Kentucky, US [1]
- Jul 3 John Couch Adams decides to determine position of an unknown planet by irregularities it causes in the motion of Uranus
- Jul 5 Thomas Cook opens first travel agency
- Jul 17 British humorous and satirical magazine "Punch" first published; it finally closed in 2002
- Jul 18 Pedro II, aged 15-years old, formally crowned Emperor of Brazil after a 10-year regency