Before there was Gmail to deliver our messages, there was pen and paper. And before that, at least in the United States in the 1800s, there were ponies.
In honor of the 155th anniversary of the Pony Express on Tuesday, Google created an animated Doodle game that commemorates the mail delivery service. If Googlers click on the Wild West-themed Doodle, they can help a pony deliver mail across America. (Just watch out for cacti).
In the video above, animator Nate Swinehart explains the history of the Pony Express and gives a behind-the-scenes look at the Doodle process.