I’ve found two more Washington DC parlors and one New York Daguerrian studio:

J. Golden – 819 Pennsylvania Avenue
Henry Ulke & Bro. – 278 Pennsylvania Avenue

The New York Daguerrian parlor is:

A.J. Beals – 156 Broadway

The address for Henry Ulke’s studio would put him today squarely on the grounds of the US Capitol, not far from the Spring Grotto, if the address is correct. Either they had a different street numbering scheme, the address is in Southeast DC instead of Northwest DC (which would put him at an even more unlikely location, a tiny triangle park just beside the Library of Congress building), or the Capitol grounds were greatly enlarged sometime between the 1870s and 1900. Given how so far so many of these studios’ locations can be accurately pinpointed today, even though the streetscape has changed a lot, I’m liking the probability that the address is correct, and that the streetscape has changed, rather than the location being inaccurate.