Why did the Liberty Bell crack?

The Liberty Bell has cracked several times, and each time it happened because the bell was rung. Each time it broke, it was repaired, but the last time it broke -- in 1846, when it was rung for George Washington's birthday -- it cracked really badly and could not be repaired. It is now on display in Philadelphia. As Agent Scully said on the X-files, "It's a big bell, with a big crack, and you have to wait in a long line." That was pretty much my experience, too. See the Related Link below for more details.