This advertisement from an 1883 DC Directory leaves a lot of questions. US Manufacturing is not listed in any directory before or after, so it seems to have been a brief enterprise and I could find nothing else about it. What happened to them? And what is the "Quick Steed"? I assume it's the two-person adult tricycle pictured, but it's not clear.
Interesting that physicians are uniquely called out, but it makes sense. No ambulances, and time-critical work to be done.
The address puts it on the NE corner of 24th and Pennsylvania where the Embassy of Spain now sits.