The westward migration of tens of thousands of Latter-day Saint pioneers in the period of 1847-69 was an unprecedented saga in American history.

The hegira to escape persecutors of the fledgling church of Jesus Christ of Latter-day Saints in the Midwest was an important factor in opening up the western reaches of the country and ultimately in bringing new states into the Union. The presence of the LDS pioneers in Utah Territory facilitated the settlement of other states as well.A hundred fifty years have passed since the first small group of 148 pioneers headed away from Winter Quarters, which later became Florence, Neb. Ahead of them lay more than 1,000 miles of prairie and mountain leading to a destination unknown as the journey began. The trek culminated in the arrival of the first permanent white settlers in the valley on July 22, 1847.

The sesquicentennial milestone is being celebrated this year with many observances, including a re-enactment of that 111-day trip from Winter Quarters to Salt Lake City. This week, hundreds of people from a dozen states and several foreign countries gathered in Florence, a suburb of sprawling Omaha, Neb.

They include Latter-day Saints eager to capture their own history and others not of the LDS faith who respect the migration as a part of American history. All are anxious for a vicarious taste of the rigors of that first migration.

Several days of preparation in Florence's Miller Park (located on the historic site of Kanesville) ended Monday as a camp of about 500 set off on the 1,000-mile-plus trek. Over the period of the entire trek up to 4,000 are expected to participate, some for a day or two, others for the duration.

Participants run the gamut from small children who likely will tire soon and be begging to ride part of the way, to seasoned history buffs determined to foot-it the entire 1,000 miles.

A century and a half have changed the terrain. Rivers have shifted and grown smaller because of the human presence. Highways, farms and towns overlie the trail in many places. Sensitivities to the environment that never troubled the pioneers have been taken into consideration. But as nearly as possible, planners have remained true to the root and the spirit of the original trek.

For those thousands taking part in the historic re-enactment, the trek will create memories to last another sesquicentennial for them and for their descendants.