Today, February 20, 2012 - in addition to being "President's Day" - is the 50th anniversary of John Glenn's successful three-orbit mission aboard Friendship 7. He was the first American to orbit the Earth, and anyone with even a cursory appreciation of the history of America's manned space program knows that it was an urgent and somewhat harrowing mission.
There is no Google Doodle celebrating that accomplishment today - at least, none so far that I can see. It was an incredibly significant event for America, in many ways more significant than Gagarin's orbit. Until John Glenn's successful mission, there existed grave and not unsubstantiated doubts that America was capable of putting a human in Earth orbit, much less bring one back safely. We really weren't sure we'd get Glenn back alive until he splashed down and was picked up by the USS Noa. His first words upon exiting the capsule (after blowing the side hatch) on the deck of the Noa were: "It was hot in there." Indeed it was. The Atlas did not shrug.
Seven and a half years later, an American placed the first human footprints on the moon.
However, Google *did* create a Doodle to celebrate the 50th anniversary of Cosmonaut Yuri Gagarin's mission on April 12, 1961. He was the first person to orbit the Earth.