In the late 1870's, taking a page from the success of nearby Eureka Springs, John Valentine Hargrove began to publicize the miraculous healing properties of the numerous springs on his and his partners' (excuse me, make that neighbors') properties.
Don, the director of the Siloam Springs Museum, tells me that there are twenty-eight Siloam Springs in all. In a stone alcove at the foot of this gazebo in Twin Springs Park are two of them. They each have distinct mineral content. A stone marker notes that this is also the site of the first medical center to take advantage of the local magic water.
The name Siloam Springs is a biblical reference. Look in Nehemiah, chapter 3. There's a list of who built and repaired what walls and what towers and which public parts of the city of Jerusalem at the end of the Hebrew Exile around 450 bc. You'll see that Shallun son of Col-Hozeh, ruler of the district of Mizpah repaired the wall of the pool of Siloam by the King's Garden as far as the steps going down from the City of David.
Then in the New Testament, Luke chapter 13, Jesus mentions that eighteen unfortunate citizens were killed when the tower in Siloam fell on them. It looks like Shallun's little fixup lasted almost 500 years. Of course, Jesus could have been making a reference to an event that was considered historical even in his own time.
In John chapter 9 Jesus heals a blind man by smearing his eyes with a poultice of spit and mud and telling him to wash it off in the pool of Siloam. That would have been the reference most familiar to the 19th Century faithful, and certainly Hargrove was going for the miraculous association. The springs aren't set up as drinking water, but I tried them out anyway (externally and internally). As usual, I didn't feel any worse and I didn't feel any better. I did notice I was markedly less thirsty, but I'll need some hard evidence before I believe the water had anything to do with that.
When Siloam Springs was incorporated in the 1880's, Hargrove's land comprised the center of town.
In the neighborhood: Siloam Springs Museum