Nineteenth Century Industrial Building Trivia

I visited a park with a nineteenth century industrial building on it recently and want to use a picture I took there as a trivia question.  For a long time I've been interested in use of slave labor in industrial settings — like all the way back to when I picked up a copy of Charles Dew's fabulous book Ironmaker to the Confederacy about the Tredegar factory in Richmond.  That place is well worth a visit, by the way — when I was living in Richmond it hadn't yet been restored.  Now it's a beautiful part of the city's presentation of their place in the Civil War.  But back to this picture; it's part of an industrial complex that's in some ways related to Tredegar and is now a park.  It's also the site of several extraordinary industrial accidents.   (Which may explain why owners of slaves who worked in this industry purchased life insurance policies on them.)  Next time I'm passing through those parts I'd like to take a picture of the cemetery that's related to some of the industrial deaths in and around this place. (Something's not working right with the previous link — it's to the California Department of Insurance's website — I hope to get that fixed soon.)