Closing a curve?

I started work on a rather lengthy curve as part of a tracing project with the assumption I could close it (join each end to make a continual line) by selecting the end vertices and pressing F

Turns out that’s not so.

And I cannot find anywhere the way to actually close the curve. Does anyone know?

Hit “C” for toggle cyclic.

Yup, C does the trick.
You might need to adjust the first and last vertices’ handles a bit, though.