On This Day in History - October 20
| Discover today's historical events and the facts. Listed here the time line of events that happened on this day in history |
| Click on the date from the below calendar to know the historical events happened on that particular day. |
|What Happened On This Day In History - October 20|
1818 October 20
49th parallel forms as border between US and Canada
1973 October 20
The Sydney Opera House opened. It is one of the most famous 20th century buildings as well as one of the most famous performing arts halls in the world.