The Confederate masses were there and he clearly saw the batteries posted along the Antietam.

Beyond the peninsula he caught glimpses of the broad Potomac.
There lay Lee before them again, and now was the time to destroy his army.

Jackson, even with his vanguard, could not arrive before night, and the main force certainly could not come from Harper's Ferry before the morrow.

Here was a full half day for the Army of the Potomac, enough in which to destroy a divided portion of the Army of Northern Virginia.
But Colonel Winchester raged again and again in vain.

There was no attack.