(New Orleans moonlight tower, c. 1882)
Before the United States became widely electrified, it was not practical to build individual street lights in many cities. That’s why some cities built “moonlight towers,” which were enormous carbon arc lamps rising hundreds of feet into the air and projecting light as far as 1,500 feet away.
(Detroit moonlight tower, c. 1900-1910).
They were called moonlight towers because their enormous lights served to replace the light of an obscured moon. They were useful, but ultimately not as practical as the street lights which replaced them. These provided more consistent illumination than moonlight towers, which could not illuminate any area blocked by a building. Changing the carbon rods could also be difficult.
(Photo of Austin via Chris Eason)
Austin, Texas, though, still retains and lights 17 of the original 31 moonlight towers that it began erecting in 1895.
(And yes, this is exactly what he was talking about, since we still have them in ATX where Linklater shot the film)
The serial killer was targeting black women in the area so plans were made to erect the towers. Of course the power that be hemmed and hawed about putting up the towers until the first white women was killed. Then they went up, lickety split.