Alfred Rosenthal, born about 1890 in Mayen near Koblenz, Germany emigrated to the USA, we know that. His parents were Daniel and Mina Loeb-Rosenthal
He was the brother of my direct ancestor; she emigrated to Israel in 1933.
Her name was Alice.
We have been unable to trace him in the US, found no immigration record of him.
How can we approach this further, any ideas?
TIA, Keren