The Liberty Bell was initially placed in the steeple of the Pennsylvania State House (now renamed Independence Hall) in 1752. Bells were rung to mark the reading of the Declaration of Independence on July 8, 1776, and while there is no contemporary account of the Liberty Bell ringing, most historians believe it was one of the bells rung. It acquired its distinctive large crack sometime in the early 19th century - a widespread story claims it cracked while ringing after the death of Chief Justice John Marshall in 1835.
When I visited Philadelphia in the 1980s the Liberty Bell was in an open plaza. Now it is housed in Liberty Bell Center and you can actually get much closer to it now.
Their web site is
here and their wikipedia page is
here.