While Americans honor the 200th anniversary of the Bill of Rights enshrining cherished freedoms, people in this rural corner of Virginia are marking the bicentennial of another historic but obscure blow for liberty.Two hundred years ago, in August of 1791, wealthy Virginian Robert Carter III began freeing more than 500 slaves from his 18 plantations - to the shock and anger of his landed peers - in the largest private emancipation in US history. It took place about 100 miles southeast of Washington, D.C., in what was to become the heart of the breakaway Southern Confederacy - more than 71 years before Abraham Lincoln's Emancipation Proclamation freed America's slaves by law in the midst of the US Civil War. Yet the action by the Virginia-born, London-schooled Carter, heir to a family plantation and shipping fortune, has gone virtually unnoticed except by specialized historians. There had never been a celebration of his good deed until recently when about 1,500 people of both races gathered in a pasture that is the site of Old Quarters Cemetery on Nomini Hall estate - one of Carter's 10 plantations - to honor Carter and the slaves he freed. The crowd gathered around a stage made from a large flatbed truck for a "Celebration of Freedom" and listened to to Gospel singers, historians, and preachers discuss Carter and his bold decision in moving terms. Carter's emancipation decision was apparently motivated by a troubled conscience over the keeping of slaves to work his 60,000 acres as well as by deep religious beliefs. But the act was stunning in a day when slaves were counted as valuable property. The first public celebration of Carter's emancipation was a combination of religious and historical pageantry.