- Aug 1 Irish Land Act gives rights to tenants of landlords in Ireland
- Aug 2 Tower Subway, the world's first underground tube railway, opens in London
- Aug 4 British Red Cross Society forms
- Aug 6 Battle at Spicheren: Prussia beats France
- Aug 8 New York Yacht Club’s first defence of America’s Cup; 'Magic' (US) defeats 'Cambria' (England) and 16 fellow defenders from NY Harbour to Sandy Hook Light Vessel on the Atlantic and return (38 miles)
- Aug 8 The Republic of Ploieşti, a failed Radical-Liberal rising against Domnitor Carol of Romania.
- Aug 15 Transcontinental Railway actually completed in Colorado
- Aug 16 Fred Goldsmith demonstrates curve ball isn't an optical illusion
- Aug 17 1st ascent of Mt Rainier, Washington, by Hazard Stevens and P. B. Van Trump
- Aug 18 Battle at Gravelotte Privat: Prussia beat France, 32,000 casualties
- Aug 24 The Wolseley Expedition reaches Manitoba to end the Red River Rebellion.