The trouble began with the alloy. A 1975 analysis by the Winterthur Museum in Delaware found that the original Whitechapel casting contained far more tin than was typical for bells of that era, possibly because the foundry used tin-heavy scraps to begin the melt. When Pass and Stow recast it, they compounded the problem by adding cheap pewter with high lead content instead of pure tin, and failed to mix the new metal thoroughly into the mold. The result was "an extremely brittle alloy which not only caused the Bell to fail in service but made it easy for early souvenir collectors to knock off substantial trophies from the rim." Speaker of the Assembly Isaac Norris, who had commissioned the bell, was so dissatisfied that he ordered a replacement from London. The Assembly ended up keeping both -- the new bell ran the tower clock, while the Pass and Stow bell waited for whatever purpose the legislature might assign.

For decades, the bell was simply the State House bell, rung for legislative sessions, elections, and public announcements. Its transformation into a national icon began not with independence but with the fight against slavery. In 1835, the New York Anti-Slavery Society's journal was the first publication to call it "the Liberty Bell," seizing on the inscription from Leviticus: "Proclaim LIBERTY Throughout all the Land unto all the Inhabitants Thereof." Abolitionists noted the bitter irony -- the bell's promise of universal liberty rang hollow in a nation built on enslaved labor. William Lloyd Garrison's newspaper The Liberator reprinted a poem in 1839 that made the point explicit: despite its inscription, the bell did not proclaim liberty to all the inhabitants of the land. It was the anti-slavery movement that gave the bell its name and its moral weight.

The Liberty Bell's association with July 4, 1776, is largely fiction. Writer George Lippard created the enduring image in an 1847 short story: an old bellman sitting morosely in the steeple until a boy races up with news that Congress has declared independence. In reality, the Declaration was not read publicly until July 8, and the State House tower may have been in too poor a condition for the bell to ring at all. The crack itself remains a mystery. It appeared sometime between 1817 and 1846 -- a popular story blames it on the tolling for Chief Justice John Marshall's death in 1835, though evidence is thin. On February 23, 1846, the Philadelphia Public Ledger reported that the bell rang for Washington's Birthday and the crack widened irreparably. "The old Independence Bell," the paper declared, "now hangs in the great city steeple irreparably cracked and forever dumb."

Between 1885 and 1915, the Liberty Bell traveled by train to seven expositions across the country, with extra stops along the way so that crowds could see it. In Biloxi, Mississippi, former Confederate President Jefferson Davis visited the bell and urged national unity. At the 1893 World Columbian Exposition in Chicago, John Philip Sousa conducted the first performance of The Liberty Bell March in its presence. Nearly two million people kissed the bell at the 1915 Panama-Pacific Exposition in San Francisco, and another ten million saw it along its rail journey there and back. But each trip worsened the cracks, and it was discovered that the bell's own watchman had been cutting off small pieces as souvenirs. After 1915, Philadelphia refused to let the bell travel again. During World War II, officials briefly considered hiding it at Fort Knox alongside the nation's gold reserves. The proposal provoked such a storm of public protest that it was abandoned.

Today the Liberty Bell sits in the Liberty Bell Center on Independence Mall, a glass-walled building opened in 2003 that looks directly toward Independence Hall. The bell weighs about 2,080 pounds, its metal 70 percent copper and 25 percent tin. The famous crack runs through the abbreviation "Philada" in the inscription, with a hairline fracture extending upward through the words "Pass and Stow," "the" before "Assembly," and the letters "rty" in "Liberty" -- the crack literally breaks the word for which the bell is named. Visitors no longer touch it, following a 2001 incident in which someone attacked it with a hammer. Beneath the Center's floor lie remnants of the President's House where George Washington's enslaved servants lived -- a proximity that keeps the bell's original contradiction alive. As historian Constance Greiff wrote: "Like our democracy it is fragile and imperfect, but it has weathered threats, and it has endured."