Jessie was originally an exact copy of the Orientation Islandsims (minus the free money), placed on the grid around April of 2003. It was first mentioned April 6th, 2003 on the Second Life forums.
On April 18th, 2003 it was announced that Jessie had been moved (next to Stanford), set as combat enabled and set public for residents to start buying plots for combat projects.
The Jessie wall is almost completely destroyed at this point, it was damaged after a large conflict over the war in Iraq, when many posters/boxes were placed over it. Linden staff, while removing these objects, also deleted a large portion of the wall, leaving only a small section in the Northwest portion of Jessie.
Currently Jessie is still combat enabled and owned by residents.