- Aug 1 Rotherhithe Tunnel under the Thames opens
- Aug 1 Lombard Street Riot erupts
- Aug 9 US-Canada border defined by Webster-Ashburton Treaty
- Aug 14 Second Seminole War declared over by Colonel Worth; Indians go on to be removed from Florida to Oklahoma
- Aug 21 The city of Hobart, Tasmania, is founded.
- Aug 29 Great Britain & China sign Treaty of Nanking, ends Opium war
- Aug 31 Micah Rugg patents a nuts & bolts machine
- Aug 31 US Naval Observatory authorized by an act of Congress