What's the point of a debt ceiling?

Imagine if your credit card company increased your limit every time you approached it. "What would be the point of having a limit?" you might wonder.

Well, I wonder the same thing about the so-called "debt ceiling." What's the point if Congress never reins in spending?  Here's a history of the debt ceiling for each fiscal year over the past decade, based on data from the Congressional Research Service and published reports:

2011: $14.294 trillion

2010: $14.294 trillion

2009: $12.394 trillion

2008: $11.315 trillion

2007: $9.815 trillion

2006: $8.965 trillion

2005: $8.184 trillion

2004: $7.384 trillion

2003: $7.384 trillion

2002: $6.400 trillion

2001: $5.950 trillion

2000: $5.950 trillion

Seriously -- what's the point of having a "ceiling" if you spend at such a rapid pace that you more than double that limit in just 10 years?

Let's look further back.  The statutory limit on the amount of U.S federal debt held by the public and the government became law with the Second Liberty Bond Act of 1917, which helped finance the United States' entry into World War I.  Up until then, the U.S. government needed approval from Congress to borrow money from the public.  With the Second Liberty Bond Act of 1917, however, the Treasury was assigned a limit to how much it could borrow from the public without seeking consent from Congress.  Thank you, Woodrow Wilson.

In 1919, the debt ceiling was set at... $43 billion.  That's billion... with a B.

Yeah, how's that debt ceiling workin' out for ya, America?