He apparently did this to stem the black market in cotton, in which some Jewish traders were involved. Grant later rescinded the order and publicly repudiated it, allowing for a titanic influx of Jews back into Kentucky, Tennessee, and Mississippi. (Okay, that never happened.) At least according to this Wikipedia entry, Grant managed to win a majority of the Jewish vote in 1868, although I'd really like to see the exit polls backing that up.
Monday, November 7, 2011
I must admit I was not aware of General Order 11, which General Ulysses Grant issued in 1862: