For starters, this was written before it was generally known that Houdini wasn't born in the United States. Also, that doesn't say Budapest! To my eye, that says Beregszasz, which until 1919 was part of Hungary and today is known as Berehove and is part of Ukraine. The city was home to a large Jewish community which you can read more about HERE.
So was Blackstone misinformed? Or does he know something we don't? If you have any ideas, feel free to share in the comments.
Thanks Diego (and Harry Sr.).