According to Randy Farmer in a 2007 post on his blog Habitat Chronicles, "During the Second Life beta test, its initial culture was starting to emerge. In my experience, worlds like this one attract early adopters of a somewhat democratic-libertarian bent — "Let's just all get along" and "Leave Real Life rules behind" often reflect the mentality of the most vocal users. But, something unusual happened this time — another virtual world, called World War II Online, was failing and its 1940s role-playing refugees migrated to Second Life, en masse. Since it provided for personal combat (hit points), death (teleport you home), and you could build just about anything, including weapons, it seemed like an ideal fit. Quickly they'd built up WWII cultural and military items, including Nazi uniforms, gear and propaganda, including flags and posters with Swastikas and the like. Eventually they took over the only remaining full-combat enabled simulator [patch of land], named Jessie, and made it their home."
About the WWII group, Kenny recalled, "They came here for combat. They said they were promised a place where they could build and create what they wanted, but what they found was a group of residents who were now against combat. Land was pretty scarce at that time (see the map of the world at that time period, below), and people had started building houses in the combat zone. In order to try to force the WWII group out, some local residents started using RL issues (this was at the time of the Iraq War) to force people to move. People put up posters of Bush and Saddam, and also Confederate flags, all over the Jessie wall. It got pretty ugly."
And at that point, the Lindens stepped in. They set the Jessie wall to "no build" and removed everything on it. According to the Jessie wikia, "The Jessie wall was 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." As an aside, both the wall and the "Entering The Outlands" sign on it are copy, so if you want to take a bit of SL history home with you, here's your chance.
When asked about the land now, Kenny commented, "The residents of Jessie tried to stick together, but some sold the land and it will never be the same. Combat was the goal of the sim, but just like RL, most people don't like war. Some of those who wanted a combat area moved to a private sim and called it New Jessie. I try to keep my land true to the idea of Jessie but others just live here. Only a few still use Her as Home."
Kenny concluded by saying, "I still think Jessie is a must see. It definitely is a huge part of the history of SL. It is the only entire sim on the mainland with damage enabled. You can see your little heart at the top of your screen when you are on Jessie. The heart is your health meter, and indicates that you can die here still to this day. I think everyone in SL should get killed at least once just for the experience! Good ole Jessie is alive and well, noob-friendly, and definitely worth visiting."
I'll leave you with a song by The Decemberists which seems an appropriate soundtrack for the story of Jessie:
"This is why
Why we fight
Why we lie awake
And this is why
This is why we fight"