Thanks for that info. I guess one category should do the trick then.
According to the 1902 bio in the ASCE transactions, the company was never M. Lassig. This may have been more of a signature than a company name.
http://books.google.com/books?id=XrvVAAAAMAAJ&pg=PA353&lpg=P...
Lassig was bought by American Bridge in 1900. This may explain the use of the same decorative design on bridges by both companies. The build date might have to determine which name was in use when the bridge was built.
Sounds good to me.
Good question, Luke. I am actually not sure if we should differentiate them or not. I am not certain when the name change occurred, or if the change had any effect on design. I think I will defer to James on this one.
I suspect that this bridge was built by M. Lassig in the 1880s or 1890s, not by the American Bridge Co. I am comparing this bridge to the Cheyenne River Bridge in Pennington Co., SD and I don't think you can correlate them because the 1927 American Bridge Co. plaque on the Cheyenne River Bridge is almost certainly on one of the newer spans.
Another South Dakota bridge gives a better comparison. It was built in 1888 by M. Lassig. http://bridgehunter.com/sd/minnehaha/bh36190/
Same cutouts in the gussets as seen here:
http://bridgehunter.com/photos/18/24/182461-L.jpg
by American Bridge Co 1927
The cutouts are also found on a bridge in chippewa falls, wi that dates to 1894