NAUVOO, Ill. — Memorializing the sacrifices of early Latter-day Saints and their martyred leaders, President Gordon B. Hinckley presided Thursday at what many believe will be the largest dedication ceremony ever held for one of the faith's temples.

With a worldwide audience of faithful members of The Church of Jesus Christ of Latter-day Saints in 72 nations joining via satellite, the first of 13 dedicatory sessions was held Thursday at the approximate hour that church founder Joseph Smith and his brother, Hyrum, were murdered in the nearby Carthage Jail on June 27, 1844.

During the dedicatory prayer, President Hinckley acknowledged the sacrifices of the martyrs and the original builders, pleading for God's protection on the new structure. He asked Latter-day Saints to recommit themselves to the same type of dedication as their ancestors.

More than 1,200 chairs were set up inside the newly rebuilt Nauvoo Temple, and still temple workers inside scrambled to find enough seating for the throngs that lined up outside the building more than two hours before the service began.

Both the temple and the nearby LDS stake center, one of thousands where the proceedings were broadcast, were filled to capacity, President Hinckley said.

Hundreds of people without tickets to either of the local venues filled the street in front of the temple during the services.

The event is widely considered to be a watershed moment for Latter-day Saints, whose members believe their gospel is Joseph Smith's restoration of Christ's original church to Earth through divine revelation.

Members believe temple ordinances were revealed by God to Joseph Smith. First practiced in the original Nauvoo Temple, Latter-day Saints believe the rituals will bind them together eternally as families in the afterlife, with proxy ordinances being performed for those who have died.

Because such beliefs are the foundation of their faith, few announcements in the church's recent history have created as much interest churchwide as that by President Hinckley when he said in April 1999 that the Nauvoo Temple would be rebuilt.

"This is one of the most significant events in our 172-year history and a defining moment for us as a people," said Elder Donald L. Staheli, president of the church's North America Central Area, which includes Nauvoo.

Many church members view the reconstruction as a vindication of the sacrifices made by their ancestors, who gave time, money and a tenth of all their assets to forward its construction.

President Hinckley's father served as a mission president in the area that includes Nauvoo during the centennial celebration of the city in 1939. President Hinckley spoke earlier in the day of his gratitude at being able to oversee the temple's reconstruction after his father had longed to see it happen. His emotion during the dedicatory ceremony was evident several times as he paused before resuming his discourse. Church members also wept openly during the proceedings.