He wrote the original Pledge of Allegiance and developed the Bellamy salute (which was used when saying the pledge / saluting the flag before it was turned into the current right hand over the heart gesture).
http://en.wikipedia.org/wiki/Francis_Bellamy
It's a masculine name to me... I could theoretically see it as a middle name for either gender, though. I can't see it as a replacement for
Isabella nn
Bella.