Seems like I remember a number of 750,000 or so engineers in the USA. I'm not sure if this is Civil's or all engineers. This would make for quite a long list.
That sounds like all engineers that are registered. I just got my WV # and it is in the 17000. If that is the average, that puts the US count at 850,000. I think Ohio is in the 70000's now. I realize there are some of those numbers are of folks that have passed on, but I also think 17000 is a little low as an average.
There has to be millions of engineers - most of which as unlicensed. I am sure NSPE keeps tabs on the numbers.