U.S. stocks had their biggest slide in a month on Monday after regional manufacturing data dented optimism about the economy's health and resource shares fell alongside commodity prices, pressured by a stronger U.S. dollar.

The Dow Jones industrial average <.DJI> dropped 187.13 points, or 2.13 percent, to close unofficially at 8,612.13. The Standard & Poor's 500 Index <.SPX> fell 22.49 points, or 2.38 percent, to end unofficially at 923.72. The Nasdaq Composite Index <.IXIC> lost 42.42 points, or 2.28 percent, to finish unofficially at 1,816.38.

(Reporting by Rodrigo Campos; Editing by Jan Paschal)