On the bottom of this slide is a transcript from his tombstone, New York 1926, which is inscribed in Hebrew with the name "Mordechai Yehudah ben Reb Tzvi," which means "Mordechai Yehudah, son of Tzvi"; and the engraved English name on the tombstone is "Max."

Believe it or not, these two documents refer to one and the same man! The rest of this lecture illustrates how we know that this is the same person.