The Lego, invented by a Danish toy manufacturer, turned 50 last week. Here are some highlights from the history of this popular interlocking brick:

March 10, 1962: After four years of lagging sales, one of the designers has the idea to add a second color to the set.

May 15, 1965: Lego scientists create a momentary tear in space-time by building a giant Lego brick out of Lego bricks.

Aug. 24, 1968: Following a long and difficult struggle, Legoland's constitution is ratified.

June 6, 1971: Lego care package is sent to brother in Vietnam.

Oct. 19, 1974: The first Lego human minifigure journeys through the human digestive system.

June 23, 1989: CEO of Megablox accidentally refers to own product as "Legos."

Jan. 21, 1998: Story rights for blue, red, and green Lego bricks optioned by Dreamworks.

Dec. 9, 2007: The company estimates that there are more than 2 billion Legos on the floor of living rooms around the world that need to be picked up.