Remember that awesome "Schoolhouse Rock" jingle about how a bill becomes a law? ("I'm just a bill. Yes, only a bill. And I'm sitting here on Capitol Hill.")
That song made its debut in 1975. The world needed a new way to understand how a bill becomes a law. And that's where the Sunlight Foundation comes in. Sunlight's Drew Vogel searched more than 60,000 bills over the past four Congresses to explore the various paths that bills take to becoming laws (or at least trying to become laws). Here's his chart (click on the image for a bigger version).
So, yeah, it's a little more complicated than "Schoolhouse Rock" made it seem.