In 1891, the Wrigley Company was formed in Chicago. Wrigley, of course, is famous for gum and for having their name on the ballpark where the Chicago Cubs have lost so many games over the years.
The Royal Canadian Air Force was formed on this date in 1924. This marked the formation of Canada’s first official national air force; the creation of the proposed Canadian Air Force in 1918 was aborted a year later when Britain decided to cut funding following the end of WWI. The Royal Canadian Air Force existed until 1968, when Canada’s army, navy and air force were integrated into the Canadian Forces.
Check out this link for rare archival footage of the first official Royal Canadian Air Force test flight. It's hard to believe they used to fly missions in these things.
Nunavut was established as a Canadian territory in 1999. It was formed from land that had formerly been part of the Northwest Territories.
Finally, in 2004 Google introduced Gmail. Some news media and bloggers were convinced Google’s announcement of Gmail was a joke, given its date of introduction and the fact that it offered unlimited inbox space (something then-unheard of from a free email provider).