From Shelby Foote’s The Civil War: Fort Sumter to Perryville (384):
When [Pierre Gustave Toutant de Beauregard‘s men] stole out of the intrenchments [at Corinth] after nightfall, they left dummy guns in the embrasures and dummy cannoneers to serve them, fashioned by stuffing ragged uniforms with straw. A single band moved up and down the deserted works, pausing at scattered points to play retreat, tattoo, and taps. Campfires were left burning, with a supply of wood alongside each for the drummer boys who stayed behind to stoke them and beat reveille next morning. All night a train of empty cars rattled back and forth along the tracks through Corinth, stopping at frequent intervals to blow its whistle, the signal for a special detail of leather-lunged soldiers to cheer with all their might. The hope was that this would not only cover the incidental sounds of the withdrawal, but would also lead the Federals to believe that the town’s defenders were being heavily reinforced.
It worked to perfection. … Daylight showed “dense black smoke in clouds,” but no sign of the enemy Pope expected to find massed in his front. Picking his way forward he came upon dummy guns and dummy cannoneers, some with broad grins painted on. Otherwise the works were deserted. …
Seven full weeks of planning and strain, in command of the largest army ever assembled under one field general in the Western Hemisphere, had earned [Halleck] one badly smashed-up North Mississippi railroad intersection.