Walnut street Bridge
Looking south. The original Court street Bridge is in background.
Photo by Lost Des Moines
BH Photo #244786
Luke, thank you. It's always exciting to find an answer.
Newspapers.com and Melissa's willingness to aide us with stuff has greatly benefitted the site, and has solved several mysteries.
Currently, I'm trying to solve the jumbled mess that is the bridge at Wapello, Iowa, but alas, I've yet to find builder-related answers, only answers to "Why did they replace the middle spans in 1903" (Flood undermined the central piers)
Nice find Luke!
This morning I had come up with the hypothesis that this bridge was CBW. I had convinced myself of it while looking at other CBW bowstrings, especially the railing on the Pittsburg, IN bridge http://bridgehunter.com/in/carroll/bh42467/
but nothing is as good as contemporary documentation!
I read and skimmed the book in the link (above) referring to the bridge. The linked paragraph refers to the first bridge, built in 1866. It was made of wood compression members and, at least, one span collapsed in September of 1869 under a load of 100 horses from Texas. "Repairs" were $7356.74 (no contractor listed). I suspect that was the cost of the bowstring.
I also found a picture of a three span 1891 King Pratt listed as Walnut Street. Des Moines.
So, in my opinion, the bridge builder of the bowstring isn't presently known.