A question in the civil war?

McClellen was poking about to see if there were any rebels in those woods. On almost finding them, he kicked 'em real hard to see what they'd do, only to find out there weren't any there after all. Then it got kinda tangled up 'cause everyone forgot their cell phone in their tent or something.

Here's a bit from Wikipedia:

On October 20...

Stone then ordered Col. Charles Devens ... to send a patrol across the river ...to gather what information ... about enemy deployments. Devens sent Capt. Chase Philbrick and approximately 20 men to carry out Stone's order. Advancing in the dark nearly a mile inland from the bluff, the inexperienced Philbrick mistook a row of trees for the tents of a Confederate camp and ... returned and reported the existence of a camp. Stone immediately ordered Devens to cross some 300 men and, as soon as it was light enough to see, attack the camp and, per his orders, "return to your present position."

This was the genesis of the Battle of Ball's Bluff. Contrary to the long-held traditional interpretation, it did not come from a plan by either McClellan or Stone to take Leesburg. The initial crossing of troops was a small reconnaissance. That was followed by what was intended to be a raiding party

The wikipedia article is nicely detailed.