How to research wether NY University (Columbia) professor Pupin was a freemason?

Question:

How to research wether NY University (Columbia) professor Pupin was a freemason?

Michael Pupin, Idvorsky-one of the inventers of long-distance telephony.

Best Answer - Chosen by Asker: His obituary may mention fraternal orders. If you have access to a decent library, his entry in an old "Who's Who" may list it.