He is most remembered today for the books he wrote about chess.

[1] Horowitz was the chess columnist for The New York Times, writing three columns a week for ten years.

Chess Review magazine was founded in 1933 as a partnership between Horowitz and Isaac Kashdan; however, Kashdan dropped out after just a few issues and Horowitz became sole owner.

Before that, Horowitz had been a securities trader on Wall Street.

Horowitz dropped out and devoted himself to chess, while the others stayed on Wall Street.

In the famous US vs. USSR radio chess match 1945, Horowitz scored one of the only two wins for the U.S. by defeating GM Salo Flohr.

In his book Modern Ideas In The Chess Openings, Horowitz proposed a defense against the Danish Gambit (1.e4 e5 2.d4 exd4 3.c3 dxc3 4.Bc4 cxb2 5.Bxb2).

Horowitz is credited as the inventor of the defense; it is called Horowitz Defense by GM Nigel Davies in the Foxy Openings DVD Dashing Danish.

Horowitz vs. Salo Flohr, US vs. USSR radio chess match 1945: 1. e4 c6 2. d4 d5 3.

Nf5 e4 (diagram) Black appears to be winning material, since White's attacked queen has no move that continues to defend the knight on f5.

A powerful shot, leaving Black with no effective way to stop the threatened mate on d8, e.g. 26...Nd5 27.Qxg4; 26...Be7 27.Qxg4!