Is the southern 1401 visible from the outside?

Visible from Constitution Ave or Madison Dr? No, not really for the former and definitely no for the latter. 

If I remember correctly, the loco is on the 12th street side of the building. You can see it there but if you try to approach it from the public sidewalk, expect to be greeted by security. If you are a good talker, you may be OK, assuming the security folks are cool. Just prepare to be stopped as you may be raising an eyebrow or two. 

Either way, don't just look at it in the window. Go in and see it all!

Went to see it today.  It's awesome!

1401 pulled the 1945 Roosevelt funeral train from Warm Springs, GA.  This locomotive has double historical value !

BTW, speculation has it that it was "stored serviceable" when retired, and has been kept under roof since that time. It is, presumably, in fine internal and external condition, and might well, mechanically, be a good candidate for restoration. But that would require some form of Divine intervention.       One of the most beautiful steam locomotives of all time.

It was a MAJOR effort to get 1401 in the Smithsonian:

She ain't goin' nowhere.

Rusty