From the ride website:

Every year tens of thousands of motorcyclists gather in the small town of Bridgeport, Alabama, to pay tribute by riding the official Trail of Tears route and bring remembrance to this tragic event in America's story. This motorcycle event is the largest organized motorcycle ride in the world. It has gathered as many as 150,000 motorcyclists producing a caravan as much as 50 miles long!

The purpose of the ride is to commemorate the event in our history known as the 'Trail of Tears.' The Trail of Tears was part of a series of forced relocations of approximately 100,000 Native Americans between 1830 and 1850 by the United States government, known as the Indian Removal. Members of the Cherokee, Muscogee (Creek), Seminole, Chickasaw, and Choctaw nations (including thousands of their black slaves) were forcibly removed from their ancestral homelands in the Southeastern United States to areas to the west of the Mississippi River that had been designated 'Indian Territory.'
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The organization that hosts the ride, the 'Alabama-Tennessee Trail of Tears Corridor Association, Inc., works to make this event a fitting remembrance and an enjoyable experience for all the motorcyclists that pay tribute. Here on this website, www.al-tn-trailoftears.net, you'll learn about the history of the Trail of Tears, see the trail firsthand, and feel the brotherhood shared by those who ride it. Join us on these web pages to see the largest motorcycle rally in America and use the information to help you plan to participate. Accommodations, ride schedules, and event information are all here at your fingertips. Join us on the ride-along part of the original Trail of Tears to honor the Cherokee, Choctaw, Chickasaw, Creek, and Seminole nations.